Final answer:
The student's question pertains to which rhetorical appeal Nixon used in a debate, with ethos, logos, pathos, and kairos as options. Without context, an exact answer is not possible, but definitions for all appeals are provided.
Step-by-step explanation:
The student is asking about which rhetorical appeal is most prominently used by Nixon in a specific part of a debate. In rhetorical analysis, we identify different strategies such as ethos, logos, pathos, and kairos. Ethos relies on the credibility or ethical appeal of the speaker, logos is based on logical argumentation and facts, pathos targets the emotions of the audience, and kairos addresses the timeliness or opportune moment for the argument. Without specifics from Nixon's debate, a precise answer is not feasible; however, each term has been defined here to illustrate what Nixon may have employed in his persuasive approach during the debate.