Answer: C. Sometimes a painting so resembles others of its era that no expert it's able to confidently decide who painted it.
Explanation: Because we can assume that the wood of the frame it's casually from Drechen's birth place, but it actually doesn't verifies that is his painting. With these kind of works it's really hard to find out the real author if we don't know what they have done before. Also, it depends where they found the painting, if someone ordinary owned it, we also can assume that he or she chose the frame. But wood frame it's not enough to know precisely the author of the painting.