Final answer:
Jefferson Davis became defensive over the release of Uncle Tom's Cabin, a novel that challenged the institution of slavery and provoked a strong reaction, notably in the South.
Step-by-step explanation:
The person who became defensive over the release of Uncle Tom's Cabin was C) Jefferson Davis. The novel, authored by Harriet Beecher Stowe, provoked outrage particularly in the South where slavery was a fundamental part of the social and economic structure. Uncle Tom's Cabin exposed the horrific realities of slavery and played a significant role in changing northern perceptions about the institution, ultimately intensifying the abolitionist movement and causing backlash from southern slaveholders and politicians like Jefferson Davis.