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 question is about a historical event in the 1980s related to U.S. foreign policy, specifically the Iran - Contra affair. In this affair, the profits from selling weapons to Iran were used to support the Contras in Nicaragua (who were opposing the Sandinista government). The other options are incorrect: there was no major effort to stop communists in Costa Rica with these funds, the proxy war in El Salvador was not funded by this specific weapon - sale profit, and there was no coup in Guatemala funded by this.

Answer:

C. support the Contras in Nicaragua.