Question

You're going to leave, but you're coming back tomorrow. What would you say?

a. Ven conmigo mañana.
b. Me siento muy bien.
c. Pues todo anda bien.
d. Mañana volveré.

Answer 1

D. Sentence means you are leaving but tomorrow your coming back. Manana is tomorrow volvere is come back

Answer 2

You would choose answer d).
Mañana means tomorrow, and volveré is the verb 'volver' (come back) in the future sense, conjugated in the 1st person, singular.
This sentence literally means 'Tomorrow I will come back'.

Hope that helps.