The answer is A.) Each country has an official language, but other languages are also common.
Spanish is the official language of most Middle American countries, but other languages are also common. For example, in Guatemala, the official language is Spanish, but Mayan languages are also spoken by many people. In Belize, the official languages are English and Spanish.
It is important to note that not everyone in a country knows how to speak the official language. This is especially true for indigenous people, who may speak their own language in addition to the official language.