There are multiple verbs in the sentence. The verb indicating future tense and the main verb is 'will try'. This is followed by 'to help' form of the verb 'help'. Since we have already used the 'to infinitive' form of the verb, the verb succeeding it cannot be used in the 'to infinitive' form. Thus, we use the next verb in bare infinitive form. So, the correct answer is 'complete'.