What Do We Mean by the Diffraction Limit of a Telescope

Multiple Choice

What do we mean by the diffraction limit of a telescope?

A) It describes the farthest distance to which the telescope can see.
B) It is the angular resolution the telescope could achieve if nothing besides the size of its light-collecting area affected the quality of its images.
C) It is the maximum size to which any telescope can be built.
D) It describes the maximum exposure time for images captured with the telescope.