The correct answer is improve.
The correct answer is [C] To improve (in value, quality, price, attractiveness); to add to (powers, qualities, etc.); to increase, raise to a higher degree; magnify; intensity.
Enhance comes from Middle English enhauncen, Anglo-French enhauncer, Old French enhaucier. The last is equivalent to en + haucier (to raise)
Examples of use:
- The candlelight enhanced her allure.
- The recent improvements enhanced the value of the article.