C) Vamos el Martes
Quando vamos a la biblioteca?:
When are we going to the library?
A) I'm going on Tuesday.
B) You're going on Tuesday.
C) We're going on Tuesday.
D) Goes on Tuesday.
I know it is correct because my original language is Spanish and I was born speaking it. I know it is the correct grammar to use while speaking Spanish. Good Luck! Hope my answer helped you!