(1)The option to be exercised in accordance with the provisions of the Explanation to sub-section (1) of section 11 in respect of income of any previous year relevant to the assessment year beginning on or after the 1st day of April, 2016 shall be in Form No. 9A and shall be furnished before the expiry of the time allowed under sub-section (1) of section 139 for furnishing the return of income of the relevant assessment year.