A study of food resources in the North Pacific between 1989 and 1996 revealed
that creatures of the seabed were suffering from dwindling food supplies, possibly resulting from increasing sea surface temperatures during the same period.
Option Elimination -
(A) that creatures of the seabed were suffering from dwindling food supplies, possibly resulting from increasing - One, we say that they suffer from dwindling food supplies, and then we say "were suffering" resulting from increasing sea temperatures - How are they suffering from both? The intended meaning is that they were suffering because of dwindling food supplies and food supplies are dwindling as a result of an increase in temperatures. That's what B does.
(B) that creatures of the seabed were suffering because food supplies were dwindling, possibly as a result of an increase in - ok
(C) that creatures of the seabed were suffering because of food supplies, which were dwindling possibly as a result of increasing - wrong meaning - suffering from food supplies.
(D) creatures of the seabed that were suffering from food supplies that were dwindling, possibly resulting from an increase in - we need that, and the same issue as C.
(E) creatures of the seabed that were suffering because food supplies were dwindling, which possibly resulted from increasing - which (pronoun) modifying verb were dwindling is wrong.