The correct answer is letter A.
The condition on the illness of a president can be challenged by the national congress, this because it is his duty to supervise the conditions of a president to govern.
In addition, it is the exclusive competence of Congress, among other duties: to resolve on international treaties and agreements that incur expenses to national patrimony; authorize the President of the Republic to declare war and to celebrate peace; approve or suspend the state of defense, federal intervention and state of siege; judge annually the accounts provided by the President of the Republic and evaluate the reports on the execution of the government plans; supervise and control the acts of the Executive Branch; analyze the concessions of radio and TV stations; plebiscites.