A group of travelers were having dinner in a restaurant .While they were eating fish, they began to tell stories about finding valuable stones inside fish . An old man ,who had listened to their conversation quietly ,said at last ,"Now I'm going to tell you a true story of my own .When I was young ,I worked in a large company in London .As is usual with other young people ,I fell in love with a pretty girl .Soon we were engaged .Two months before our marriage ,I was suddenly sent to Edinburgh on business .My stay was a bit longer than I had expected .At last my work was done and I left for home .Before I left Edinburgh , I bought a nice diamond ring for my sweet-heart .On my way to London ,I was looking through a newspaper .It was then that I learned of my sweet-heart's getting married to another man. I was so sad that I threw the diamond ring into the water. A few days later, when I was eating fish ,I bit on something very hard .What do you think it was? "The diamond ring ," shouted his friends . "No," said the old man sadly ,It was a fish bone. The young man bought a diamond ring   _
soon after he started working in Edinburgh . when he got engaged to his sweet-heart . after her marriage. when he was going to return.
Question: A group of travelers were having dinner in a restaurant .While they were eating fish, they began to tell stories about finding valuable stones inside fish . An old man ,who had listened to their conversation quietly ,said at last ,"Now I'm going to tell you a true story of my own .When I was young ,I worked in a large company in London .As is usual with other young people ,I fell in love with a pretty girl .Soon we were engaged .Two months before our marriage ,I was suddenly sent to Edinburgh on business .My stay was a bit longer than I had expected .At last my work was done and I left for home .Before I left Edinburgh , I bought a nice diamond ring for my sweet-heart .On my way to London ,I was looking through a newspaper .It was then that I learned of my sweet-heart's getting married to another man. I was so sad that I threw the diamond ring into the water. A few days later, when I was eating fish ,I bit on something very hard .What do you think it was? "The diamond ring ," shouted his friends . "No," said the old man sadly ,It was a fish bone. The young man bought a diamond ring   _
A. soon after he started working in Edinburgh .
B. when he got engaged to his sweet-heart .
C. after her marriage.
D. when he was going to return.
Answer: