The correct answer is C. Alvar Nuñez Cabeza de Vaca was the first European explorer in the area where Texas is now located.
Explanation:
Alvar Nuñez Cabeza de Vaca was a Spanish explorer in America. On November 6, 1528, he became the first known European to set foot in present-day Texas as he landed near the present Corpus Christi along the Gulf of Mexico's coast. There he was for a time a prisoner of the American natives. After six years, he managed to escape through the Rio Grande, going trough present-day Texas and northern Mexico. He also discovered the cataracts at Iguazu and explored the Paraguay River in South America.