What is another name for an object line? A.
solid line
B.
section line
C.
hidden line
D.
center line

A. Solid Line

Explanation:

"A visible line, or object line is a thick continuous line, used to outline the visible edges or contours of an object. A hidden line, also known as a hidden object line is a medium weight line, made of short dashes about 1/8” long with 1/16”gaps, to show edges, surfaces and corners which cannot be seen (Open Oregon)."

It doesn't directly say that, but that's what I'm inferring from its context.

Okay, I hope this helps in some way! Have a wonderful day! :)