Which of the following is a vector quantity?
A. Force
B. Work
C. Energy
D. Power

Hint: To find the appropriate solution of the given question, we need to primarily brush up the concept of vector and scalar quantities.
Vector quantities are quantities that are fully described by its magnitude and direction whereas Scalar quantities that are fully described by its magnitude alone.

Complete answer:
Now we shall be looking into each of the options and try to find the appropriate solution to the given question.
Force can be formulated as the cross product of mass and acceleration, and has both magnitude and direction. Hence, Force is a vector quantity.
Work is the product of Force and displacement which are vector quantities, thus, work is scalar by definition. Hence, Work is a scalar quantity.
Energy does not possess any significance of its direction, thus, is considered scalar. Hence, energy is a scalar quantity.
Power is the ratio of Energy to time, both of which are scalar quantities, thus, Power is scalar by definition. Hence, Power is a scalar quantity.

Therefore, the correct option would be (A) Force.

Note:
One is advised to carefully observe that while talking about the second option which is work, we wrote that since it is a product of Force and displacement which are vector quantities, thus, work is scalar by definition . One must remember that such products of two vector quantities are only scalar when they are dot products of their components and vector when they are cross products of their components.