Which country is NOT a member of the PAHO?

The correct choice is that Portugal is not a member of the Pan American Health Organization (PAHO). PAHO is an international public health agency that focuses on health initiatives in the Americas. Its membership primarily comprises countries within the Americas, specifically those in North America, South America, and the Caribbean.

Canada, Peru, and Venezuela are all located within the Americas and are therefore eligible to be members of PAHO. These countries participate in regional health initiatives and collaborate on public health matters pertinent to their respective populations. In contrast, Portugal is situated in Europe and does not fall under the jurisdiction or geographic scope covered by PAHO, which explains why it is not a member of this organization.