Pop Quiz Time!

I have three example images here (A, B, and C). Two lenses were used (a 24mm and a 100mm). Can you tell which lens was used for each? Can you tell if the aperture is the same in all three or different?

Example A:

Example B:

Example C:

Post your answers in the comments section. Once we have a couple of comments I'll post a description of the images and background information.

Thanks!