Amaravati School of Sculpture developed on the banks of which river?
Krishna river
Krishna river is correct.
The Amaravati School of art grew around the great stupa at Amaravati in present-day Andhra Pradesh, on the banks of the lower Krishna, mainly under the Satavahanas and later the Ikshvakus.
Its reliefs were carved in white limestone and show scenes from the Buddha's life and Jataka tales with lively, crowded compositions.
Gandhara art grew in the north-west near the Indus region, and Mathura art grew on the Yamuna, so the other rivers do not fit.
Statement I : The rich sculptural tradition of Mathura is distinguished by its principal medium, the white spotted red sandstone
Statement II : The white spotted red sandstone is locally available in Mathura region