Correct Answer: (d) Enhance
Note: Enhance- To improve the quality, amount, or strength of something.
Undermine- to make someone less confident, less powerful or weaker.
Cripple- To cause severe damage to something so that it cannot operate effectively.
Weaken- to (cause to) become less strong, powerful, effective. determined, or
Spoil- diminish or destroy the value or quality of something.