Final answer:
The correct sentence is option B, 'John and I cooked dinner for the family.'
Step-by-step explanation:
The correct form of the pronoun in the sentence is B. The sentence 'John and I cooked dinner for the family' uses the subjective form of the pronoun 'I' as the subject of the sentence. The subjective form of the pronoun should be used when the pronoun is the subject of a sentence or when it is used after a linking verb.
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