The OPEC oil cartel is included in Venezuela and Ecuador, the only members in the Americas.
The OPEC oil cartel includes Venezuela and Ecuador, the only members in the Americas.
The OPEC oil cartel is included in Venezuela and Ecuador, the only members in the Americas.
The OPEC oil cartel includes Venezuela and Ecuador, the only members in the Americas.
The verb "include" relates parts to whole. If the whole is the subject, the verb must be active: "[whole] includes the [parts]." Here, the OPEC oil cartel is the "whole", and the individual nations are the "parts."