The sentence refers to the person "he", emphasizing that he personally said it.
The correct reflexive pronoun "himself" is used to emphasize the subject "he".
The correct sentence is:
"He himself said so."
Thus, the correct answer is Option A ("He himself said so").
Arun’s present age in years is 40% of Barun’s. In another few years, Arun’s age will be half of Barun’s. By what percentage will Barun’s age increase during this period?