The correct option is A GMT +5:30
Indian Standard Time represents the time zone the country has adopted with the intention of having the entire country following it.
Given that India has adopted the 82.5°E longitude as its standard, the difference between London and New Delhi will be: 4 minutes x 82.5° (Since the earth rotates by 1° every four minutes). Additionally, with India being to the east of Greenwich, it will be ahead of GMT.