Answer:
C. Both added land to the U.S., land which previously belonged to Mexico.
Step-by-step explanation:
The treaty of Guadalupe Hidalgo ended the Mexican-American war and under it's terms Mexico had to give up a great portion of their land to the United States (including parts of present-day Arizona, California, New Mexico, Texas, Colorado, Nevada, Utah).
The Gadsden Purchase was an agreement between the U.S. and Mexico for a 29,670 square mile portion of Mexico. The U.S. payed $10 million and it is part of present-day Arizona and New Mexico.