Final answer:
Jack won the jury over with the eloquence of his testimony, which implies a combination of rhetorical strategies such as ethos (credibility), pathos (emotional appeal), and logos (logical arguments).
Step-by-step explanation:
Jack won the jury over with the eloquence of his testimony. While emotion, logic, and authenticity could also affect a jury's perspective, the word 'eloquence' specifically refers to the persuasive and impressive way in which he spoke, potentially including aspects of logical evidence and ethos.
Eloquence often combines the art of speaking with persuasive rhetorical strategies such as ethos, pathos, and logos. Ethos refers to the credibility or ethical appeal of the speaker, pathos to the emotional connection, and logos to the logical arguments presented. Considering this, the answer that encompasses the right balance of credibility, emotion, and rationality implied in the question seems to be eloquence.