AIM GMAT wrote:In addition to her work on the miocene homicide fosiil record, Mary Leakey contributed to archaelogy with her discovery of the earliest direct evidence of hominid activity and painstakingly documenting East African paintings.

(A) Leakey contributed to archaeology with her discovery of the earliest direct evidence of hominid activity and painstakingly documenting
(B) Leakey contributed to archaeology by her discovery of the earliest direct evidence of hominid activity and by painstakingly documenting
(C) Leakey was a contributor to archaelogy with her discovery of the earliest direct evidence of hominid activity and with her painstaking documentation of
(D) Leakey's contributions to archaelogy include her discovery of the earliest direct evidence of hominid activity and her painstaking documentation of
(E) Leakey's contributions to archaelogy include her discovering the earliest direct evidence of hominid activity and painstaking documentation of

The sentence intends to talk about the contributions of Leakey to field of archaeology. She contributed 3 things to that field:
- work on the miocene homicide fossil record
- discovery of the earliest direct evidence of hominid activity
- documentation of East African paintings

So, all these elements need to logically and structurally parallel.

the first part of Non-underlined portion is the our first item, which will serve as our starting point for parallelism.
(a) and (b) are out because "(painstakingly) documenting" is not parallel with the former items.
(e) also breaks the parallelism "discovering the earliest"

between (c) and (d)
in (c) later 2 part of the items break the parallelism with the first part. Please see below:
- her work on the miocene homicide fosiil record
- with her discovery of the earliest direct evidence
- with her painstaking documentation

IMO D

Wow singh great explanation , i have one more doubt , what is "her" referring in option D . I mean doesnt the possesive makes it confusing ?

AIM GMAT wrote:Wow singh great explanation , i have one more doubt , what is "her" referring in option D . I mean doesnt the possesive makes it confusing ?

Actually in D, "her", which is an possessive pronoun refers back to possessive noun "Leakey's X".

D it is, singh has given such a wonderful explanation, i dnt thnk anythgn else is necessary