Explanation:

Amaravati School:In the southern parts of India, the this developed on the banks of Krishna river, under the patronage of the Satvahana rulers. While the other two schools focused on single images, Amaravati School put more emphasis on the use of dynamic images or narrative art.
Mathura School flourished on the banks of the river Yamuna in the period between 1st and 3rd centuries B.C. The sculptures of the Mathura School were influenced by the stories and imageries of all three religions of the time – Buddhism, Hinduism and Jainism. The images were modelled on the earlier Yaksha images found during the Mauryan period. The Mathura School showed a striking use of symbolism in the images. The Hindu Gods were represented using their avayudhas.
Gandhara school of Art developed in the western frontiers of Punjab, near modern day Peshawar and Afghanistan. The Greek invaders brought with them the traditions of the Greek and Roman sculptors, which influenced the local traditions of the region. Gandhara School flourished in two stages in the period from 50 B.C. to 500 A.D. While the former school was known for its use of bluish-grey sandstone, the later school used mud and stucco for making the sculptures. The images of Buddha and Bodhisattvas were based on the Greco-Roman pantheon and resembled that of Apollo.