No nation in the world has experienced as significant a decline in its Yucaipa tree population as our nation. Yet only our nation imposes a law prohibiting the use of Yucaipa tree-bark oil in cosmetics. The purpose of this law in the first place was to help maintain the Yucaipa tree population, at least in this nation. But the law is clearly uncecessary and therefore should be repealed.

Which of the following, if true, would most seriously weaken the conclusion drawn in the passage?

(A) This nation contains more Yucaipa trees than any other nation.
(B) Yucaipa tree-bark oil is not used for any consumer goods other than cosmetics.
(C) The demand for cosmetics containing Yucaipa tree-bark oil is expected to decline in the future in other nations while continuing unabated in this nation.
(D) In other countries, labor used to harvest Yucaipa trees for cosmetics is less expensive than comparable labor in this nation.
(E) In this nation, some wild animals eat Yucaipa tree bark, thereby contributing to their destruction

OA is

Why is D even considered? The explanation in the book is that labor in this nation is more expensive, so producing cosmetics in this nation would be more expensive than other nations. Therefore, the tree population might not reduce significantly even if the law were repealed.

If it's ok to repealed the law, it would strenthen the argument then