The correct answer is option- 2: The Greeks. This means that the gold coins were first introduced in India by the Greeks.
Option- 1: The Kushanas were a Central Asian dynasty that ruled over parts of northern India from the 1st to the 3rd century AD. While they did mint coins, they were not the first to introduce gold coins in India.
Option- 3: The Sakas were another Central Asian tribe that ruled over parts of India during the 1st and 2nd centuries AD. Like the Kushanas, they also minted coins, but they were not the first to introduce gold coins.
Option- 4: The Parthians were an ancient civilization in what is now Iran. They had trade relations with India, but they were not credited with the introduction of gold coins.
Therefore, the correct answer is option- 2: The Greeks.