Final answer:
The correct verb form to complete the sentence is 'entrevistaba' in the imperfect tense.
Step-by-step explanation:
The correct verb form to complete the sentence is entrevistaba.
Mientras la reportera entrevistaba al candidato, el fotógrafo tomaba fotos de las personas que asistieron a la rueda de prensa.
The verb 'entrevistaba' is in the imperfect tense, which is used to describe ongoing or habitual actions in the past. In this sentence, it indicates that the reporter was interviewing the candidate continuously or regularly in the past.
Learn more about Verb conjugation in Spanish