SC: Why painting the face and perfuming the body

[sinhavis]

Why painting the face and perfuming the body should have persisted throughout recorded history has been the subject of a substantial amount of anthropological and psychological speculation.

(A) Why painting the face and perfuming the body should have persisted
(B) How painting the face and perfuming the body could be persistent
(C) That painting the face and perfuming the body are persisting
(D) Painting the face and perfuming the body persisting
(E) The persisting of face painting and body perfuming

source : internet testmagic.com
Why A is chosen over D

[JonathanSchneider]

The speculation is not on the face-painting itself, but on WHY the face-painting occurred in the first place.

Moreover, D is incorrect because the word "persisting" seems to describe the word "body," not the actions previously described.