Explanation:

The first century CE onwards, Gandhara (now in Pakistan), Mathura in northern India and Vengi in Andhra Pradesh emerged as important centres of art production. Buddha
in the symbolic form got a human form in Mathura and Gandhara. The sculptural tradition in Gandhara had the confluence of Bactria, Parthia and the local Gandhara tradition. The local sculptural tradition at Mathura became  so strong that the tradition spread to other parts of northern India. The best example in this regard is the stupa sculptures found at Sanghol in the Punjab. The Buddha image at Mathura is modelled on the lines of earlier Yaksha images whereas in Gandhara it has Hellenistic features.

http://ncert.nic.in/ncerts/l/kefa104.pdf