What is the condition for two vectors to be Collinear?

Correct option is D

Two vectors are said to be collinear if they lie along the same line or if one vector is a scalar multiple of the other. In other words, the two vectors are either pointing in the same direction or in exactly opposite directions, but they must be aligned along the same line.
The vectors should be parallel to the same line — This is the correct condition for collinearity. If two vectors are parallel to the same line, they are collinear.​