Answer: d. vamos, va
Este viernes es la quinceañera de mi prima, Melina. Nosotros vamos a tener un tiempo increíble. Melina va a tener mucha gente en su fiesta. Será una fiesta especial.
This Friday is the fifteenager of my cousin, Melina. We are going to have an incredible time. Melina is going to have many people at her party. It will be a special party.
Explanation: the subject in the first blank is "Nosotros", that is a first-person in the plural, so the verb must be conjugated in this form "vamos", and the subject in the second blank is "Melina", that is a third-person in the singular, so the verb must be conjugated in this form "va".