Light from Each Part of the Source Being Observed Falls

Multiple Choice

Light from each part of the source being observed falls on each part of the primary mirror of a Newtonian telescope not obstructed by the secondary mirror. The important consequence of this is that

A) the image does not have a dark spot indicating the presence of the secondary mirror.
B) the image is not darkened (overall) because of the presence of the secondary mirror.
C) cheaper spherical mirrors can be used rather than a more costly parabolic mirror.
D) the secondary mirror can be made as large as needed without influencing the quality of the image.