The correct answer is C.
The Battle of the Alamo took place in 1836 and it was a landmark event in the Texian Revolution, a conflict through which Texans aimed to resist to the centralist Mexican goverment.
The Mexican forces attacked the Alamo Mission, near to San Antonio, under the command of Santa Anna. The Texians defenders were rapidly killed with intense cruelty. This demonstration of violence encouraged many Texians to join the Texian army due to a renewed and more intense desire for revenge and independence.