Answer
a) is correct.
Work Step by Step
Momentum is a vector and can be found using this formula: $$\vec{p}=m\vec{v}$$
This equation already indicates the direction of momentum is the same as the direction of velocity.
Therefore, 2 objects having the same momentum means their momentum direction is the same, and so is the direction of velocities. a) is correct.
However, the magnitudes of their velocities do not have to be similar. Since $p=mv$, 2 objects with different speeds but having appropriate masses can end up having the same momentum. b) is incorrect.
