School children are using mobile phone applications to do their homework, which seem to beincreasing during summer vacations. But instead of blaming students for their behavior, we should say noto too much homework. This is important because by using mobile phone applications to do theirhomework, students don't add much to their knowledge, says an article in Guangzhou-based YangchengEvening News. Excerpts  : Using mobile phone applications to do homework is no different from copying from someone else'swork. This is the opinion of a vast majority of teachers. Students who seek cell phone apps help to do theirhomework will pay dearly during major exams when they cannot seek the help of such applications, theteachers say. The heavy load of homework Chinese students are burdened with, said to be the heaviest in the world,has led to the popularity of these applications. Senior high school students in China rarely go to bed before 11 pm. A report in Shanghai published in2013 showed that students in the city on average spend 28.2 hours in class every week, the 9th highestamong 65 countries and regions surveyed. Also, they spend an average of 13.8 hours a week doinghomework, most in the world. There is no association between the amount of homework one does and the amount of knowledge onegathers. In fact, a research by Australian experts shows that the result is exactly the opposite: the morehours students spend doing homework, the less effective they will be in gaining knowledge. The United States is one of the countries where students do little homework, but that has not damagedthe country's academic status in the world. So, it's time Chinese schools understood this fact and freed students of the unnecessary burden ofhomework. The cause of the students' using mobile phone applications to do their homework is  _  .
the heavy burden of homework the advance of modern technology the pressure of the students' parents the influence of other countries
Question: School children are using mobile phone applications to do their homework, which seem to beincreasing during summer vacations. But instead of blaming students for their behavior, we should say noto too much homework. This is important because by using mobile phone applications to do theirhomework, students don't add much to their knowledge, says an article in Guangzhou-based YangchengEvening News. Excerpts  : Using mobile phone applications to do homework is no different from copying from someone else'swork. This is the opinion of a vast majority of teachers. Students who seek cell phone apps help to do theirhomework will pay dearly during major exams when they cannot seek the help of such applications, theteachers say. The heavy load of homework Chinese students are burdened with, said to be the heaviest in the world,has led to the popularity of these applications. Senior high school students in China rarely go to bed before 11 pm. A report in Shanghai published in2013 showed that students in the city on average spend 28.2 hours in class every week, the 9th highestamong 65 countries and regions surveyed. Also, they spend an average of 13.8 hours a week doinghomework, most in the world. There is no association between the amount of homework one does and the amount of knowledge onegathers. In fact, a research by Australian experts shows that the result is exactly the opposite: the morehours students spend doing homework, the less effective they will be in gaining knowledge. The United States is one of the countries where students do little homework, but that has not damagedthe country's academic status in the world. So, it's time Chinese schools understood this fact and freed students of the unnecessary burden ofhomework. The cause of the students' using mobile phone applications to do their homework is  _  .
A. the heavy burden of homework
B. the advance of modern technology
C. the pressure of the students' parents
D. the influence of other countries
Answer: