Solution:
1. When we talk about a line , it means it has infinite length and there are infinite number of points on it.
And there is not a single way to name a line, there are infinite number of ways to name a line by placing any two points on the line .We don't need to put bar(-) while naming a line by considering two points on the line.
So, Option B: The line has infinitely many points. is true option.
2. PM -= A line segment
So, it has definite length and we need to put bar (-) over it.It can be written either as PM or MP having bar over it.
Option B: MP−→− is true option.