In the context of the Ill Gandhara School of Art, the image of Buddha is a prominent feature. The Ill Gandhara School of Art was a style of Buddhist art that flourished in the area of present-day Pakistan and Afghanistan during the 2nd and 3rd centuries CE.

Option 1: Buddha - This is the correct choice. The art of the Ill Gandhara School primarily focused on depicting the life and teachings of Buddha. The artwork featured images of Buddha in various forms, such as seated, standing, or in meditation. The sculptures and reliefs often showcased intricate details, such as the Buddha`s serene facial expression and unique ornamentation.

Option 2: Krishna - This is not the correct choice. Krishna is a Hindu deity, and his depiction is more commonly found in Hindu art, not in the Ill Gandhara School of Art.

Option 3: Mahavira - This is not the correct choice. Mahavira is the central figure in Jainism, a religious tradition that emerged around the same time as Buddhism. However, the Ill Gandhara School primarily focused on Buddhist art and did not prominently feature images of Mahavira.

Option 4: Shiva - This is not the correct choice. Shiva is