Answer: B. iremos
Mañana nosotros iremos al museo a las diez de la mañana.
Tomorrow, we will go to the museum at ten in the morning.
Explanation: "Mañana" is the future time, so the verb must be conjugated in the future. Since the subject in this sentence is "nosotros", which is a first-person in the plural, the verb must be conjugated in this form. Nosotros iremos.
