Answer:
c-Yes, if the two vectors are in the same direction.
e. Yes, if one of the vectors is zero.
Step-by-step explanation:
Lets take
The magnitude of the two vectors are A and B and they are at angle θ
Then the Sum of these two vectors

Resultant R

if the angle between these vectors is zero.It means that they are in the same direction.
θ = 0



R=A+B
If the one vector is zero vector.
Therefore the answer will be C and e.