According to the passage, a life preserver should be first of all ______.

A．1 ) the author refers to the person ______.A. who has not been instructed how to use a life preserverB. who has a little experience in using a life preserverC. who uses a life preserver without permissionD. who becomes nervous before a disaster

A．with as few strings as possible
B．capable of being worn on both sides
C．according to each wearer's size
D．comfortable and light to wear