Final answer:
Combining vectors is simple when they are parallel. If they are in the same direction or if they are in opposite directions, the statement is true. Therefore correct answer is option 1.
Step-by-step explanation:
Combining vectors is indeed simpler when they are parallel, irrespective of whether they are in the same direction or if they are in opposite directions. This statement is true. If two vectors are parallel and in the same direction, they can be added straightforwardly by adding their magnitudes. Vectors in opposite directions (antiparallel) can also be combined simply by subtracting their magnitudes if they are of the same dimensions; this could be considered as adding a negative scalar to a vector.
Vector addition is commutative and associative, which means that the order in which we add vectors does not affect the result. Moreover, multiplying a vector by a scalar affects the vector's magnitude but not its direction, unless the scalar is negative, in which case the direction is reversed (antiparallel).
Orthogonal vectors, which are at right angles to each other (90 degrees apart), have a different method for addition, often involving the use of trigonometric functions or a coordinate system like the Cartesian coordinate system for breaking down the vectors into components and then combining them.