The correct answer is B. excites.
The word "tantalize" means to tempt or tease someone by offering them something they cannot have. In this case, the speaker is tempted by the diamond necklace in the window, but they know they cannot afford it. This makes them feel excited and frustrated at the same time.
The other options are incorrect because they do not accurately describe the speaker's feelings. The speaker is not humiliated by the necklace, nor are they teased or amplified by it.
