Answer:
A. enhance
Step-by-step explanation:
Enhance means to intensify, increase, or further improve the quality or value of something. As a consequence, considering the purpose of the paragraph is to cause someone to do something through reasoning or argument, enhance is the only word with a positive connotation that best fits the gap.
The rest of the alternatives are incorrect because they do not evoke a feeling of influencing someone to do something as well as enhance.