单项选择题

Questions 15 to 17 are based on the following passage, At the end of the passage, you will be given 15 seconds to answer the questions
Now listen to the passage.

Why didn’t the captain worry at first

A.He didn’t detect the enormous iceberg.
B.He didn’t realize the seriousness of the disaster.
C.He thought the ship was unsinkable.
D.He was horrified by the accident.