How to Claim DTAA Benefit in TDS Return?

How to claim DTAA benefits in 27Q Return in case of amount  paid for software. Which code to be selected?

A- In case of lower deduction or no deduction on account of certificate under section 197
B- In case of no deduction on account of declaration under section 197A

C- In case of deduction of tax at higher rate due to non-availability of PAN

S- For software acquired under section 195 (Notification 21/2012). Applicable from FY 2012-13 onwards.