Can’t really help, because there is a dialogue that you have to read in order to answer the questions
Duda que él encuentre un buen empleo que le pague bien.
Tu necesitas unas vacaciones para. Descansar y relajarse.
Entiendo is the correct answer because "entender," the original form of the verb, is a stem changer, e--ie, and the "yo" form in present tense ends with -o.
