Question

¿Qué puedo traer a la fiesta? —_____ Ud. el pan.

Answer 1

Traiga el pan Ud.

Why?
B) Trae could be correct, but it's present tense, not future tense.

C) Traen is past present tense, not future tense.

D) Traigan is for a group, here it's only one person, Ud.

This is how we get A) Traiga, because we use the present tense and the one-person word.

Hope this helps!~