Right answer: baño
IN SPANISH:
Yo quiero la habitación individual con un cuarto de baño privado.
IN ENGLISH:
I want the single room with a private bathroom.
This sentence refers to something inside the hotel room. This means that you are asking for a private room. The more logical answer is that this room is a bathroom. This sentence is given in the simple present and the verb that is being used here is querer whose conjugation for the first person singular (yo) is quiero.
