Answer:
It's C
Explanation:
Because it is the one that makes more sense.
If we translate the whole sentence it would be like this:
-marisa is going to <u>plan</u> a ten day trip to ecuador.
-marisa va a <u>planificar</u> un viaje de diez días a ecuador.
The correct choice to fill the blank and complete the sentence is, tu.
Juanita, ¿es tu camiseta?
Sí, es mi camiseta.