The sentence ___ est le president actuel du Cameroun ? means "___ is the current president of Cameroon?" This question tests knowledge of French interrogative words (mots interrogatifs).
The correct answer is Qui (Who). The question asks about a person - specifically, the identity of the current president. Qui is the interrogative pronoun used to ask about people.
The other interrogative words ask about different things:
Ou' (a rendering of Ou, where) asks about place or location: Ou est la gare ? (Where is the station?)
Quand (when) asks about time: Quand est-ce qu'il arrive ? (When does he arrive?)
Que (what) asks about things or actions: Que fais-tu ? (What are you doing?)
The complete sentence is: Qui est le president actuel du Cameroun ? - Who is the current president of Cameroon?
