Vectors need direction and magnitude to exist, otherwise, it becomes scalars that do not require direction to be expressed.
eg - Velocity is a vector as it needs direction, but speed is scalar and does not need direction
hope this helps
Answer:
a. All quantities in physics are not vectors. b. A vector may have either magnitude or direction. c. The vector's length should be proportional to its magnitude. d. Two vectors can be added only if they have the same direction.