Final answer:
The correct verb form to complete the sentence is ">fue.
Step-by-step explanation:
The correct verb form to complete the sentence is fue.
This is because the sentence is in the past tense, indicating an action that happened in the past, and the verb ser (to be) is conjugated as fue for the third person singular in the past.
For example, 'Él fue el mejor crítico de cine. Trabajó en nuestro periódico por treinta años.' means 'He was the best film critic. He worked at our newspaper for thirty years.'
Learn more about Spanish verb conjugation