Which statement about acceleration is true?

The statement regarding acceleration as "the result of an unbalanced force exerted on a body" is accurate because acceleration is fundamentally interconnected with Newton's second law of motion. According to this law, an unbalanced force acting on a mass results in the acceleration of that mass. Essentially, when forces acting on an object are not equal and opposing, the net force leads to a change in the velocity of that object over time—this change in velocity is what we define as acceleration.

In this context, other options do not appropriately capture the essence of acceleration. For instance, the notion of acceleration as "time / velocity" misrepresents the relationship, as it fails to acknowledge the concept of force or unbalanced forces that trigger acceleration. Similarly, viewing acceleration simply as "force / time" ignores the mass aspect involved, which is critical in relating force to acceleration. Lastly, stating that acceleration is "the rate of change of displacement" technically describes a concept called velocity rather than acceleration itself. Velocity denotes how quickly displacement changes over time, while acceleration is specifically about the change in velocity.