Select the correct direct form of the given sentence.

The old man asked the boy where the postman was.

The old man said to the boy, "Where is the postman?" 

The correct direct form of the given sentence is:

The old man said to the boy, "Where is the postman?"

When converting indirect speech to direct speech, we need to make the following changes:

• Add quotation marks.
• Change the reporting verb to one that is appropriate for the mood of the sentence in indirect speech. In this case, the reporting verb "asked" is changed to "said" because the sentence in indirect speech is an interrogative sentence.
• Change the pronouns to match the subject and object of the direct speech sentence. In this case, the pronoun "he" in the indirect speech sentence is changed to "the postman" in the direct speech sentence because the object of the direct speech sentence is the person the old man is asking about.
• Change the verb tense to match the tense of the reporting verb. In this case, the verb tense in the indirect speech sentence is present tense, so the verb tense in the direct speech sentence is also present tense.

Therefore, the correct direct speech sentence is:

The old man said to the boy, "Where is the postman?"