Lord Buddha’s image is sometimes shown with the hand gesture, called ‘Bhumisparsha mudra’. it signifies:

The correct answer is both (a) and (b) are correct.

Explanation:

The Bhumisparsha Mudra, also known as the "earth-touching gesture," is one of the most iconic and significant hand gestures in Buddhist art and iconography. In this mudra, Lord Buddha is depicted sitting in meditation with his right hand reaching down to touch the earth with fingertips pointing downwards, while his left hand rests palm-up in his lap.

This gesture symbolizes the crucial moment of Buddha's enlightenment beneath the Bodhi tree when he faced Mara, the demon king symbolizing temptation, desire, and illusion. Specifically:

1. Calling the Earth to Watch Over and Protect: As Mara sought to disturb Buddha's deep state of meditation with various temptations and demonic forces, Buddha touched the ground, summoning the earth goddess (Sthavara/Vasundhara) to watch over him and safeguard his spiritual pursuit against Mara's disruptions.
2. Witness to Purity and Virtues: When Mara challenged Gautama Buddha's right to reach enlightenment, questioning his worthiness, Buddha touched the earth to call it as a witness to his purity, chastity, infinite perfections (paramitas), and righteous deeds performed across countless past lives.

Since both descriptions accurately explain the profound symbolic meaning of the Bhumisparsha mudra, the statement that both (a) and (b) are correct is the complete and accurate answer.