There was great interest when a big hole mysteriously appeared in the middle of a field. Engineers were called in to explain how it had got there. They offered various explanations but were not at all sure how the hole had been caused, it was thought that a large bomb which came suddenly exploded, but it was not possible to prove this. A simple, but highly improbable explanation was offered by a man who declares to know well about "flying saucers"; the strange objects which are round in shape and are said to visit the earth from outer space. The man's explanation may have been nonsense  , but at least it was imaginative. At any rate, it was far more interesting than the one given by the army. After examining the ground carefully the man declared to have seen special marks on the soil quite near the hole, these, he said, could only have been caused by a flying saucer. Moreover the leaves on some bushes nearby had turned yellow because of a strange hot gas which had come from the saucer just before it landed. Even a small tree some way off appeared to have been burnt slightly. A small piece of metal found in the hole itself gave further proof that a strange object had been there. According to the man, it was quite clear that people from another world had been going around the earth trying to pick up information, when something had gone wrong. Because of this they had been forced to land in a field so that the damage could be repaired. The hole had been caused when the saucer struck the earth, while the strange marks nearby were made when it took off again. This, said the man, was the simplest explanation of how the hole had appeared. Judging from the interest the public took in the matter, there must be quite a few people who secretly believe or hope that this simple explanation is the true one. The man found a lot of proofs except   _  .
special marks on soil near the hole yellow leaves on some bushes nearby a small piece of meal in the hole the remains of the flying saucer
Question: There was great interest when a big hole mysteriously appeared in the middle of a field. Engineers were called in to explain how it had got there. They offered various explanations but were not at all sure how the hole had been caused, it was thought that a large bomb which came suddenly exploded, but it was not possible to prove this. A simple, but highly improbable explanation was offered by a man who declares to know well about "flying saucers"; the strange objects which are round in shape and are said to visit the earth from outer space. The man's explanation may have been nonsense  , but at least it was imaginative. At any rate, it was far more interesting than the one given by the army. After examining the ground carefully the man declared to have seen special marks on the soil quite near the hole, these, he said, could only have been caused by a flying saucer. Moreover the leaves on some bushes nearby had turned yellow because of a strange hot gas which had come from the saucer just before it landed. Even a small tree some way off appeared to have been burnt slightly. A small piece of metal found in the hole itself gave further proof that a strange object had been there. According to the man, it was quite clear that people from another world had been going around the earth trying to pick up information, when something had gone wrong. Because of this they had been forced to land in a field so that the damage could be repaired. The hole had been caused when the saucer struck the earth, while the strange marks nearby were made when it took off again. This, said the man, was the simplest explanation of how the hole had appeared. Judging from the interest the public took in the matter, there must be quite a few people who secretly believe or hope that this simple explanation is the true one. The man found a lot of proofs except   _  .
A. special marks on soil near the hole
B. yellow leaves on some bushes nearby
C. a small piece of meal in the hole
D. the remains of the flying saucer
Answer: