Which U.S. state was formed from the Republic of Texas?

The correct answer is Texas. The Republic of Texas existed as an independent nation from 1836 until it was annexed by the United States in 1845. Prior to its annexation, Texas declared independence from Mexico and operated as a sovereign republic for nearly a decade. In the context of U.S. state formation, Texas was directly transformed from the Republic of Texas into the state of Texas upon its admission to the Union.

The other choices are states that were never part of the Republic of Texas in the same sense. For instance, California and New Mexico were territories that faced different histories of colonization and statehood, while Oklahoma was part of the Indian Territory and later organized as a state. None of these states directly emerged from the Republic of Texas as Texas did, making Texas the correct response in this context.