Question

fill in the blank: il est douteux que les enfants ______ service à leur papa.
○ rende
○ rendrent
○ rendent
○ rendre

Explanation:

In French, the structure "Il est douteux que..." requires the subjunctive mood. The verb "rendre" (to do a favor, to help) with the subject "les enfants" (third - person plural) in the subjunctive present has the form "rendent". Let's analyze the other options: "rende" is the first - person singular subjunctive, which doesn't match the subject "les enfants"; "rendrent" is the indicative present tense (third - person plural), not subjunctive; "rendre" is the infinitive form, which is not suitable here.

Answer:

C. rendent