The largest number of copper coins in northern and north western India were issued by

The correct answer is (b). The Kushans issued the largest number of copper coins in northern and northwestern India.

The Indo-Greeks were a group of Indo-Scythians who ruled parts of the Indian subcontinent from the 2nd century BCE to the 1st century CE. They were known for their coinage, which was often of high quality and featured Greek and Indian motifs. However, the Indo-Greeks did not issue as many copper coins as the Kushans.

The Sakas were a group of Indo-Scythians who ruled parts of the Indian subcontinent from the 2nd century BCE to the 4th century CE. They were known for their coinage, which was often of high quality and featured Greek and Indian motifs. However, the Sakas did not issue as many copper coins as the Kushans.

The Pratiharas were a Rajput dynasty that ruled parts of northern India from the 7th century to the 11th century CE. They were known for their coinage, which was often of high quality and featured Hindu and Buddhist motifs. However, the Pratiharas did not issue as many copper coins as the Kushans.

The Kushans were a group of Indo-Scythians who ruled parts of Central Asia and the Indian subcontinent from the 1st century BCE to the 3rd century CE. They were known for their coinage, which was often of high quality and featured Greek and Indian motifs. The Kushans issued the largest number of copper coins in northern and northwestern India.