[讨论]请教一道GMATprep题

Recently documented examples of neurogenesis, the production of new brain cells, include the brain growing in mice when placed in a stimulating environment or neurons increasing in canaries that learn new songs.

A. the brain growing in mice when placed in a stimulating environment or neurons increasing in canaries that

B. mice whose brains grow when they are placed in a stimulating environment or canaries whose neurons increase when they

C. mice's brains that grow when they are placed in a stimulating environment or canaries' neurons that increase when they

D. the brain growth in mice when placed in a stimulating environment or the increase in canaries' neurons when they

E. brain growth in mice that are placed in a stimulating environment or an increase in neurons in canaries that

答案是E，我在A和E之间徘徊了很久，觉得两个在平行并列上都有点问题，最后选了A，还请NN们指点一下呀～～谢谢～！！

怎么都没人理我呢？？