Correct Answer: I said that I had taken a lot of precautions after my surgery.

Solution : The correct choice is the second option.

Indirect speech, also known as reported speech or indirect discourse, is a way of reporting what someone else has said without quoting their exact words.

The steps of construction are as follows:

• There would be no change in the reporting verb of the indirect speech.
• The simple past tense "took" is changed to the past perfect tense "had taken".
• The connector "that" is used to introduce the reported clause.

Therefore, the correct answer is: " I said that I had taken a lot of precautions after my surgery."