External forces are
A. Always balanced
B. Never balanced
C. May or may not be balanced
D. None of these

Hint: Forces can be classified into two types:
1. Internal forces
2. External forces
For our purposes, we will simply say that external forces include the applied force, normal force, tension force, friction force, and air resistance force. And, the internal forces include the gravity forces, magnetic force, electrical force, and spring force.

Complete step-by-step answer:
Talking about the forces:
External Forces: External forces are capable of changing the total mechanical energy of an object, they are sometimes referred to as no conservative forces.
Common Examples are:
1. applied force
2. normal force
3. tension force
4. friction force
5. air resistance force
Internal Forces: Internal forces do not change the total mechanical energy of an object; they are sometimes referred to as conservative forces.

Common Examples are:
1. gravity forces
2. magnetic force
3. electrical force
4. spring force
External forces sometimes create acceleration of the body. If total external force acting on a body is zero, then that body must not be accelerating; thus we say the external forces are said to be balanced but otherwise, they are said to be unbalanced.
From this we’ve got a brief idea now we can say that external forces are balanced or may not be balanced. Hence option C is correct.

Note: External forces are forces caused by external agents outside of the system. Internal forces are forces exchanged by the objects in the system. To find what part should be taken as external and internal, mechanical systems should be clearly defined. In external forces momentum is considered if it is elastic.