The correct answer is option 4. The statement "The largest number of coins issued by the Guptas were of copper" is not correct.

During the Gupta Empire, the kings indeed issued a large number of gold coins called Dinar (option 1). These gold coins were highly valued and were used for trade and commerce.

Option 2 is also correct. Chandragupta II, Kumaragupta I, Skandagupta, and Budhagupta issued silver coins. These silver coins were of lower value compared to the gold coins but were still widely used for transactions.

Option 3 is also true. The obverses (front side) of the Gupta coins were indeed carved with images of the kings, depicting their authority and power. On the reverse side, deities and religious symbols were often engraved.

Therefore, option 4 is the incorrect statement. While copper coins were also issued by the Guptas, they were not the largest number of coins issued. Gold and silver coins held more prominence in the Gupta coinage system.