mousemic

This is a  weakening type question.

Common sense: Investment in Education and Job Training promotes growth in Economy.

A) simply proclaims that there is another reason to explain the economic growth. Whether investment in eduation and job training would lead to economic growth is not proven right or wrong. But it is a possible reason. That is enough to cast an unfavorable light on the hypothesis the author is trying to undermine.

There is another facet of the problem one needs to consider: the main conclusion.

The author agrees with the widely held hypothesis and he is trying to refute an undermining evidence (most strict regulation is associated with the highest growth.) His conclusion is that "This fact does not show that environmental regulations promote growth," and your job is to find a premise which supports this main conclusion.