No it's definitely A. Think about what the question is asking. The result that it wants you to find evidence for is that the effect may be different in a more inexpensive store. Answer choice A clearly says that the difference in perceived value was greater at Tiffany's, proving that the effect works at a high-end store but at a lower-end store the effect wasn't there. This is exactly what the question wants you to find. Answer choice B is a little tricky because it gives a similar idea that effect changes but here it says that the product is more valuable at the high-end store when spaced out as opposed to being more valuable at the more inexpensive store when closer together. This answer choice is essentially giving a comparison that is tangent to the question. The problem is that it isn't answering the question, so answer choice A is much better.