单选题 The passage is chiefly about ______.

A、 an effort to protect an endangered marine species
B、 the civilian use of a military detection system
C、 the exposure of a U.S. Navy top-secret weapon
D、 a new way to look into the behavior of blue whales

【正确答案】 B

【答案解析】提示出现在第三段相关内容。