Each option pertains to numismatics, or the study of coins, during a specific era in Indian subcontinent history.

Option 1 correctly states that the Indo-Greeks introduced bilingual (Greek and Kharosthi/Brahmi) and biscript legends on their coins, demonstrating their bicultural influence.

Option 2 is also correct that the Kushanas minted large quantities of gold and copper coins. This reflects their economic power and the prevalent trade during their rule.

Option 3 refers to the Satavahanas, who are known to have issued coins made of multiple materials including silver, copper, lead, and potin (a bronze-like alloy).

Option 4 is incorrect, making it the answer to the question. Absence of Negama (Nigama) coins does not necessarily suggest the declining power and authority of merchant guilds. Other factors could cause a lack of coin presence, and Nigama guilds could exert power regardless of their coin issuance. Therefore, it`s not accurate to conclude that a lack of these coins reflects a decline in the power and authority of merchant guilds.