Question

during the 1980s, profit from the sale of weapons to iran was used to
stop the communists in costa rica
start a proxy war in el salvador
support the contras in nicaragua
stage a coup détat in guatemala

Explanation:

This refers to the Iran-Contra affair of the 1980s, where the U.S. secretly sold weapons to Iran and used the proceeds to fund the Contra rebels in Nicaragua, despite a congressional ban on such funding. The other options do not align with this specific event.

Answer:

support the Contras in Nicaragua