OPEC influences world affairs through: providing aid to countries under Communist threat.

controlling oil prices.

All of the choices are correct.

training soldiers.

controlling oil prices.

Explanation:

OPEC is an acronym for organization of the petroleum exporting countries. It is an intergovernmental organization that was established on the 14th of September, 1960 in Baghdad, Iraq by Juan Pablo Pérez Alfonzo and Abdullah Tariki at the Baghdad Conference with five (5) member countries, which includes Iraq, Saudi Arabia, Kuwait, Venezuela and the Republic of Iran.

The headquarters of the organization of the petroleum exporting countries (OPEC) is in Vienna, Austria since 1965 and its universally accepted currency is US Dollars (USD) indexed per barrel of crude oil.

The main objective and purpose of the organization of the petroleum exporting countries (OPEC) is to coordinate and create uniformity in petroleum policies among its 13 member countries namely Nigeria, Gabon, United Arab Emirates, Algeria, Saudi Arabia (the de facto leader of OPEC), Angola, Iraq, Equatorial Guinea, Iran, Kuwait, the Republic of the Congo, Venezuela, and Libya, so as to facilitate the regular supply of petroleum to consuming nations at a fair and stable price per barrel.

Hence, organization of the petroleum exporting countries (OPEC) influences world affairs through controlling oil prices.

the three answers (for plato at least) are:

b-condemned sola fida 

d-set rules for establishing seminaries and for educating clerics in the seminaries 

f-recommended moderation in the sale of indulgences and banned the sale of false indulgences