Which sentences use intensive pronouns correctly? Select the two correct answers.

To determine which sentences use intensive pronouns correctly, we first need to understand what an intensive pronoun is. An intensive pronoun is a pronoun that reinforces or emphasizes a noun or pronoun in the same sentence.

Let's review the sentences provided and check for the correct usage of intensive pronouns:

1. "I myself will take care of the problem." - This sentence correctly uses the intensive pronoun "myself" to emphasize the pronoun "I." The correct usage of the intensive pronoun reinforces the subject of the sentence.

2. "They cooked dinner for themselves." - This sentence correctly uses the intensive pronoun "themselves" to emphasize the pronoun "they." The correct usage of the intensive pronoun reinforces the object of the sentence.

3. "She said he himself was responsible for the accident." - This sentence does not use an intensive pronoun correctly. The pronoun "he" does not need to be reinforced or emphasized.

4. "We need to prepare ourselves for the upcoming challenges." - This sentence correctly uses the intensive pronoun "ourselves" to emphasize the pronoun "we." The correct usage of the intensive pronoun reinforces the subject of the sentence.

Based on the explanations given, the two correct sentences that use intensive pronouns correctly are:

1. "I myself will take care of the problem."
2. "They cooked dinner for themselves."