哪位大虾帮忙进来看看这道题

       A migraine typically afflicts one side of the head, lasts for hours or days, and may recur as infrequently as once every other month or often, as daily.

(A) as infrequently as once every other month or often, as

(B) as infrequently as once every other month or as often as

(C) infrequently, as often as once every other month, or often, like

(D) infrequently, like once every other month, or often, like（B）

(E) infrequently, like once every other month, or as often as

答案是B 

哪位高手能给解释下B和D对比，为什么B更好。先谢过拉^_^