PT 8 S4 Q11

A distemper virus has caused two-thirds of the seal population in the North ... ...

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 unprecedentedly steep drops in population.
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Practice Set: "Stronger" Questions, Set 3 - Difficult/Uncommon Mix (25Q)