I think your answer should be either the third choice or second choice. They both make sense to me but the other two are definitely not it. Hope this helps! =^-^=
The Wilmot Proviso pointed to trouble ahead in the debate over the expansion of slavery.
In 1846, Congressman David Wilmot of Pennsylvania introduced the proviso as an amendment to an appropriations bill in connection with the peace treaty being negotiated with Mexico. His amendment stipulated that any territory gained from Mexico would be free, not allowing slavery. Wilmot's amendment passed in the House of Representatives, but was unable to get approval in the Senate. The high-intensity debate over slavery and the expansion of slavery was evidenced by how things went with the "Wilmot Proviso."
<span>Hot summers led to a long growing season for cash crops such as tobacco and cotton which were labor intensive.</span>
D: by trying out policies that might later affect the entire nation
