Select the correct indirect form of the given sentence.

She said to Madhu, “Please post this letter.”

She requested Madhu to post that letter.

The correct indirect form of the given sentence is: She requested Madhu to post that letter.

The other options are incorrect:

• She said Madhu to post that letter. This is incorrect because we do not use the preposition "to" after the reporting verb "said".
• She ordered Madhu that post this letter. This is incorrect because the reporting verb "ordered" is too strong for a request.
• She told Madhu to post this letter. This is also correct, but it is less formal than using the word "requested".