Answer: D. a prime minister who serves as the head of government
Step-by-step explanation:
Neither Mexico nor Brazil have a Prime Minister instead having a President who is both the Head of State and the Head of Government.
In both states, the President is the Chief of the Executive branch of Government as well as the Commander In-Chief of the armed forces much like the President of the United States.
The current President of Mexico is Andrés Manuel López Obrador whilst that of Brazil is Jair Bolsonaro.