Answer : 4. "The most conspicuous bravery or self-sacrifice an land, air or sea but not in the presence of the enemy"
Explanation :

(D) The most conspicuous bravery or self-sacrifice on land, air, or sea but not in the presence of the enemy.

The Ashoka Chakra is a peacetime military decoration awarded for acts of the most conspicuous bravery or some daring or pre-eminent act of valor or self-sacrifice on land, at sea, or in the air. It is not specific to actions in the presence of the enemy, distinguishing it from some other military decorations.