Why did Texas colonists, like Stephen F Austin, object to the merger of Texas and Coahuila

These are the answer choices associated with the question:

A. Mexico feared Texas was becoming too powerful and they might lose control.

B. It prevented more empresarios from entering Texas and bringing colonists.

C. Slavery became illegal throughout Coahuila and all of Mexico

D. The location of the state capital was too far away for Texans to participate in government.

And this is the correct

C. Slavery became illegal throughout Coahuila and all of Mexico

Explanation:

Texas colonists from the United States, like Stephen F Austin, mostly came from the Deep South (with many others coming from Appalachia), and because of this, they wanted to expand the plantation economy of the Deep South in Eastern Texas, and for that, they needed slaves.

However, slavery had become illegal in Mexico, and this is the main reason why they opposed the Union of Coahuila and Texas. Their main goal was to make Texas an independent nation, and then, to ask for annexation with the United States.