President of Teachers' Union: Many people are convinced that declining test scores in our district are the fault of teachers. Yet, our school district has recently seen a large influx in the rise of enrolling students who do not speak any English at all. Nearby districts that have seen a similar influx of students who do not speak English have all experienced much larger drops in test scores. It is a testament to the skill and dedication of our teachers that test scores in our district have dropped so little.

The bold statement in the argument plays which of the following roles?

(A) It is the main conclusion of the argument.
(B) It is a finding that the argument seeks to explain.
(C) It introduces an explanation that the argument seeks to refute.
(D) It provides support for the main conclusion of the argument.
(E) It is a judgment that the argument corroborates.

OA C

Source: Manhattan Prep