Correct Answer : Option (A) - Mesopotamians
The Indus Valley people traded with the Mesopotamians.
Mesopotamia of harappan times is now Iraq and Kuwait. The composition of trade was almost exclusively to luxury goods like spices, textiles and precious metals.
Mesopotamians didn't have many natural resources. So, they depended mostly on the trade to get what they wanted. Parthians are the ones who ruled in NW frontier India during later ancient period of India.