I got it wrong but this is what I've picked up from the other explanations, feel free to drop a reply in case there are any errors.
When investigating an incident from the distant past, it is a common occurrence that there is partially or completely conflicting accounts of the same event and, therefore, to construct a realistic historical hypothesis, one should collate as many records as one can.A. When investigating an incident from the distant past, it
is a common occurrence that there is partially or completely conflicting
accounts of the same event and, therefore, to construct a realistic historical hypothesis, one should collate as many records as one can - eliminated as the wrong SV, Accounts is plural and would require 'are'
B. To construct a realistic historical hypothesis, one should collate as many records as one can because when investigating an incident from the distant past, it is a common occurrence that there are partially or completely conflicting accounts of the same event
To construct a realistic hypothesis,
one should collate records
as many as one can - sentence perfect on its own, correct idiom usage of as many as, subject reference is correct,
because when investigating an incident from the distant past - dependent on previous sentence
it is a common occurrence that there are partially or completely conflicting accounts of the same event - if I'm not wrong the 'it' is a dummy word and we cannot identify what 'it' is referring to, but logically the sentence makes sense.
C. When investigating an incident from the distant past, it is a common occurrence that there are partially or completely conflicting accounts of the same event, and
to construct a realistic historical hypothesis,
one should therefore collate as many records as
he can - eliminated as he is incorrect as it is not parallel with 'one'
D. When investigating an incident from the distant past, a common occurrence
is that there are partially or completely conflicting accounts of the same event, so
one should collate as many records as
they can in order to construct a realistic historical hypothesis- one and they. One is singular, they is plural so incorrect.
Also if anyone sees this, can someone confirm if the usage is correct? : a common occurrence is that there are .. - It just sounds so wrong.
E. To construct a realistic historical hypothesis, one should collate as many records as one can because when investigating an incident from the distant past, it commonly occurs that there
is partially or completely conflicting
accounts of the same event - eliminated as the wrong SV, Accounts is plural and would require 'are'