As, Parallelism

[karthikpandian19]

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

[Bill@VeritasPrep]

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

The use of "like" in C, D, and E is incorrect.

A is not parallel "as infrequently as...or often, as"

B is parallel "as infrequently as...or as often as"

[GmatKiss]

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

IMO: B

[karthikpandian19]

OA is B

[ihatemaths]

only B has parallelism.

[bryan88]

+1 for B