Answer:
That the Texans should prepare for war against Mexico
Explanation:
Following the eventual release of Stephen F. Austin in 1835. He realized that Texas is on the verge of rebellion and it appears that Texas and Mexico's future no longer aligned.
Therefore, in a speech he gave in March 1836 at Louisville, he urged the people of Texas to revolt and prepare for war.
Hence, in this case, the correct answer is "That the Texans should prepare for war against Mexico."