Critical Reasoning

A distemper virus has caused two-thirds of the seal population in the North Sea to die since May 1988. The explanation for the deaths cannot rest here, however. There must be a reason the normally latent virus could prevail so suddenly: clearly the severe pollution of the North Sea waters must have weakened the immune system of the seals so that they could no longer withstand the virus.

Which one of the following, if true, most strongly supports the explanation given in the argument?
(A) At various times during the last ten years, several species of shellfish and seabirds in the North Sea have experienced unprecedented steep drops in population.
(B) By reducing pollution at its source, Northern Europe and Scandinavia have been taking the lead in preventing pollution from reaching the waters of the North Sea.
(C) For many years, fish for human consumption have been taken from the waters of the North Sea.
(D) There are two species of seal found throughout the North Sea area, the common seal and the gray seal.
(E) The distemper caused by the virus was a disease that was new to the population of North Sea seals in May 1988, and so the seals' immune systems were unprepared to counter it.

please explain !!

[spoiler]OA : A[/spoiler]

sandeep232 wrote:A distemper virus has caused two-thirds of the seal population in the North Sea to die since May 1988. The explanation for the deaths cannot rest here, however. There must be a reason the normally latent virus could prevail so suddenly: clearly the severe pollution of the North Sea waters must have weakened the immune system of the seals so that they could no longer withstand the virus.

Which one of the following, if true, most strongly supports the explanation given in the argument?
(A) At various times during the last ten years, several species of shellfish and seabirds in the North Sea have experienced unprecedented steep drops in population.
(B) By reducing pollution at its source, Northern Europe and Scandinavia have been taking the lead in preventing pollution from reaching the waters of the North Sea.
(C) For many years, fish for human consumption have been taken from the waters of the North Sea.
(D) There are two species of seal found throughout the North Sea area, the common seal and the gray seal.
(E) The distemper caused by the virus was a disease that was new to the population of North Sea seals in May 1988, and so the seals' immune systems were unprepared to counter it.

please explain !!

[spoiler]OA : A[/spoiler]

IMO A

The passage clearly speaks bout the immune system of the seals to have become weak in North Sea due to the pollution. Hence, we would look for a solution which is supporting that.

(A) - seems as viable option becuase it can be seen that the pollution of the North Sea has caused not only seals but seabirds and selfish to perish. Let''s keep this solution as an option
(B) - this is weaking the passage. Hence, incorrect
(C) - if the water was polluted, the fish would never be used for human consumption.Hence, it's weakening. Incorrect
(D) - irrelevant
(E) - this is again weakeaning the argument. Hence, incorrect.

The only option left is A.

Hope the ans is clear now..