How did the cotton gin support the institution of slavery

it gave the whites a reason to get more slaves

Explanation:

While it was true that the cotton gin reduced the labor of removing seeds, it did not reduce the need for slaves to grow and pick the cotton. In fact, the opposite occurred. Cotton growing became so profitable for the planters that it greatly increased their demand for both land and slave labor.

Explanation:

d.he wanted to send diplomats to communist countries.

the answer to your question is true