In your footsteps Anandnk
A and B are wrong as "it" has no clear referent. Also, overlooking seems to introduce a participial phrase which should in fact modify the immediately preceding noun "same site". Basically, "same site" would have done the action of overlooking... which is wrong
C "overlooking that" is not idiomatic. you "overlook the possibility that"
D was explained by anandnk