If you look at the first part of the question, the speaker says “tu”, which means “you”, so you would pick the option that has the “tu” conjugation of the verb “estar”. Then, for the second part of the sentence, if you don’t know what cansadísimo means, you can look at the other two options, “contento”. Paying attention to cognates, “contento” sounds like “content”, and “enfermo” sounds like infirm, which means sick. The two are not synonyms, so you would go with the option that has both the “tu” conjugation and “cansadísimo”.
It would be "Diana prefiere que nosotros tragamos la comida para las vacaciones" because you have to conjugate the verb "tragar" for Nosotros, so you would replace the "-AR" ending with "Amos".
