【正确答案】 A

【答案解析】[听力原文]
   M: Using a life jacket can be the critical factor in surviving a boating accident. It is state law that there must be one life jacket for each person on the boat, and anyone 12 years of age or younger must wear a life jacket at all times. Any boat 16 feet and longer must also carry one life saver or similar device. Life jackets should be easily accessible on the boat, not stowed away in closed compartments or with other gears stowed on top of them. There are also different types of life jackets, so it's important to get one that fits properly, especially for children. Life jackets can be purchased at most marine supply stores or boat dealers, where you can try on several until you find one that suits your needs. This is a public service announcement from Department of Safety Boating Program and this station.
选项A正确。选项B错误，“学会求生”这个话题太过宽泛。选项C错误，这不是播报的主要目的。选项D错误，播报中提到船舶的安全准备，但也不是主要目的。