Satellite radio transmissions, a popular feature in car stereos, differ from those of AM and FM radio, which is sent directly from earthbound towers and then to a car stereo.
A. which is sent directly from earthbound towers and then to a car
B. which are sent directly from earthbound towers to a car's
C. sent from earthbound towers and then directly to a car
D. sending them directly from earthbound towers to a car's
E. being sent directly from earthbound towers to a car
答案是选B
做题时在B和E之间纠结，然后题目第二句末尾“car stereos”选择了E“a car stero”，后面看解析并没有纠结是car stereo还是car's stereo。
然后对比前面的which are sent和being sent，为什么会选择which are sent，或者为什么being sent会被排除掉？
谢谢各位大神帮忙解答！