Why A is wrong?

sana.noor wrote:There are far fewer children available for adoption than there are people who want to adopt. Two million couples are currently waiting to adopt, but in 1982, the last year for which figures exist, there were only some 50,000 adoptions.
Which of the following statements, if true, most strengthens the author's claim that there are far fewer children available for adoption than there are people who want to adopt?

(A) The number of couples waiting to adopt has increased significantly in the last decade.
(B) The number of adoptions in the current year is greater than the number of adoptions in any preceding year.
(C) The number of adoptions in a year is approximately equal to the number of children available for adoption in that period.
(D) People who seek to adopt children often go through a long process of interviews and investigation by adoption agencies.
(E) People who seek to adopt children generally make very good parents.

Notice the SHIFT IN LANGUAGE between the premise and the conclusion.
Premise: In 1982, there were only fifty thousand ADOPTIONS.
Conclusion: There are far fewer CHILDREN available.
The assumption is the number of ADOPTIONS is linked to the number of available CHILDREN.
There could MANY REASONS for the small number of adoptions: a slow bureaucracy, the high cost, etc.
The argument assumes that there is NO OTHER REASON for the small number of adoptions and that the ONLY EXPLANATION is a lack of available CHILDREN.
The correct answer choice will strengthen the conclusion that the small number of adoptions is due to a lack of available CHILDREN.

Answer choice C: The number of adoptions in a year is approximately equal to the number of children available for adoption in that period.
This answer choice strengthens the conclusion that the reason for the small number of adoptions is a lack of available CHILDREN.

The correct answer is C.

Answer choice A: The number of couples waiting to adopt has increased significantly in the last decade.
This answer choice strengthens the PREMISE that there are many parents -- at the moment, two million parents -- waiting to adopt.
But it tells us nothing about why there are so few ADOPTIONS.
The correct answer choice must strengthen the conclusion that the small number of adoptions is due to a lack of available CHILDREN.
Eliminate A.

Thanks mitch!