Correct Answer : Option (A) - Aditya L-1

Note : ISRO has categorized its six Mega Missions (excluding Chandrayaan-B) in two broad categories- Defined Missions: The mission includes XPoSaT and Aditya L-1. Undefined Missions: The missions which are still in the planning stage. These missions are Mangalyaan-2, Venus Mission, Lunar Polar Exploration and Exoworlds.