1) Vincent y Monica están cansados.
Cansados is plural for cansado/a
4) Paloma está enamorada con su novio.
Enamorada is singular feminine
5) Los abuelos de Irene están contentos.
Contentos is plural for contento/a
Hope this helped :)
Answer: Va
Explanation: There are multiple conjugations for the verb "ir" each corresponding to the subject of the sentence/ the one who carries out the action. In this sentence, Katiana should be in the el/ella/usted form. The el/ella/usted form of "ir" is va.