Indian air force pension imp query!

Tax (Student) (165 Points)

03 March 2017  

Assessee is a pensioner from Indian Air Force.. 

He receives Dearness Allowance (DA) & Dearness Allowance Arrears.. Are these taxable?

He also received arrears of ONE RANK ONE PENSION in instalments.. But income "didn't" cross basic exemption limit for that financial year.. Will these be taxable & relief under Section 89 applicable? 

He was also in receipt of arrears of pension under normal course for a financial year.. Income "CROSSED" basic exemption limit for that financial year.. Will these arrears be taxable and relief under Section 89 available?