Final answer:
The sentence that includes an irregular verb is 'The children watched the rabbits in the field during the picnic.'
Step-by-step explanation:
The sentence that includes an irregular verb is: The children watched the rabbits in the field during the picnic.
An irregular verb is a verb that does not follow the regular pattern of conjugation. In this sentence, the verb 'watched' is an irregular verb because its past tense form does not end in -ed.
Examples of other irregular verbs include 'go' (past tense: went), 'eat' (past tense: ate), and 'come' (past tense: came).
Learn more about Irregular verbs