Jen delivers a speech to the local government body about the need to clean a lake in the town. While speaking, Jen consciously uses simple, fluent English so that her audience clearly understands her message. Jen also logically explains the consequences of having a dirty lake in the town. Given this information, it is evident that Jen uses while delivering her speech
A) hasty generalization to establish initial credibility
B) arguments from example
C) vocal expression to enhance her credibility
D) the rhetorical strategy of pathos

C) vocal expression to enhance her credibility

Explanation:

Effective communication revolves around seven factors or characteristics, popularly known as the 7 Cs. These are:

In the current scenario, Jen is highly focused on conveying the correct, clear and complete meaning of her words. She uses simple words so everyone can understand them. She structures her sentences in a clear, concise, to the point manner so everyone hears and understands exactly what she means.

On the other hand, as she appeals to the audiences reason and logic through her arguments, she is also employing the rhetorical device of logos.  

the answer that is correct is the last option.