A line is an undefined term because it describes something that does not have width or depth. thus, option describes something that does not have width or depth is correct
Which ray can be said as belonging to a line segment?
If the ray lies onto the considered line segment(overlapping), then it can be said belonging to the considered line segment.
(Line segment has 2 fixed ends, whereas a ray has one end only, another end is not fixed)
A line segment is a straight line with finite length, and thus, have to endpoints (points on either ends).
A line can extend its length in both sides infinitely. It contains arrowheads indicating it can extend.
A line is an undefined term because it describes something that does not have width or depth. thus, option describes something that does not have width or depth is correct