On multiple choice exams you're supposed to pick The Right Answer. (C) is definitely correct as all it says is that the test is valid - using other words. So if you know what validity is, you should pick (C). Anything you might say about (A) depends on a number of interpretations and assumptions -- it is not the most unambiguous option I've seen but it's not too bad either provided that one uses the minimum amount of common sense.
But your reasoning about (A) is not based on common sense. Although one may interpret the words "consistently replicated" as a requirement that the measurement results should be exactly numerically precisely the same every time, from now until the end of the world as we know it, this is almost certainly not what is meant when anyone uses these words. In other word, stating that the results can be "consistently replicated" does not mean that the results are "perfectly reliable". This may be a question of nuance, if you're picky, but that's how these words are used.
Another problem with your interpretation of (A) is that it does not use the information given in the question text. The text says that the inventory is valid. On the other hand, for saying that an inventory is not "perfectly reliable" (i.e., your interpretation of "consistently replicable") one needs no information about the inventory whatsoever. There is no inventory that is "perfectly reliable" -- except the one that spits out the same score every time.
Thirdly, you say, "Just because you are taking the same test, you are not going to get the same score every time. You are going to get a score that reflects your depression level at the time of taking the test." But here you're mixing the stability of a trait (depression) with the reliability of a measure (BDI). Perfect reliability implies that a person should get the same score provided that his or her depression level has not changed. This is why test-retest (or any other method we can use with inventories) is not a pure measure of reliability -- in real world, there is always a fluctuation of trait levels.