Investigations along the Solo river in Indonesia have led some archeologists to debunk the idea of an era in which Homo Erectus had still survived in then Homo Sapiens’ inhabited areas.

(A) in which Homo Erectus had still survived in then Homo Sapiens’ inhabited areas
(B) in which Homo Erectus still survived in areas inhabited by Homo Sapiens
(C) when Homo Erectus still survived where there were areas inhabited by Homo Sapiens
(D) when Homo Erectus had still survived in current Homo Sapiens areas
(E) when Homo Erectus still survived in areas that were then Homo Sapiens’

in choice E, "Sapien's area" dose not mean "inhabited by Sapien". meaning is changed. E is gone.

Solution

Credit: http://www.gmatfree.com/module-68/the-s ... lanation=1

Creating a filter: in this question, the construction "in which" may stand out. The answer choices show that "in which" and "when" are alternatives we must choose between. Both phrases, "in which" and "when," convey meaning accurately here. More of a problem is the phrase "in then Homo Sapiens' inhabited areas," an awkward string of words.

Applying the filter: (B) looks better and clear. Choice (C) has strange phrasing that leaves us uncertain whether the two groups are in the same area, as the sentence intends to say. Choice (D) has the same problem as (A). Choice (E) distorts the meaning of the sentence; the intended meaning isn't that any areas belonged to Homo Sapiens; we're talking about cohabitation. The correct answer is (B).

if we want to use had done, we need "did" or "have done", both of which show a part action or an action beginning in the past. but this past action must be in time sequence logically with the action presented by had done. appearance of an action presented by "did" or "have done" dose not guarantee the correct usage of "had done". this is a hard point of usage of had done.

we can not use "had survived " here because the action "survived' has no time relation with '"have led". these two actions are not in sequence of time.

second error
area of "homo" is not mean "area inhabited by Homo".
choice a and e are wrong
look at choice C
when Homo Erectus still survived where there were areas inhabited by Homo Sapiens - "still survived"? We are talking about event that's over in the past.

"survive where there were areas inhabited by Homo" mean that the large place in which they survived contains smaller areas which are inhabited by Homo. this meaning is different from the meaning that Erectus survive in area inhabited by Homo.

choice c is wrong

Option C:

when Homo Erectus still survived where there were areas inhabited by Homo Sapiens

'where' is wrong because the intended meaning should be like this:

when Homo Erectus still survived in areas inhabited by Homo Sapiens