Which one of the following effects of creation of black money in India has been the main cause of worry to the Government of India?

1. The question asks for the main cause of worry to the Government of India arising from the creation of black money. 2. Black money refers to funds earned through illegal activities or legal income that is concealed to avoid taxation. 3. Option (A), diversion of resources to real estate and luxury housing, is an effect, but primarily a consequence of having unaccounted wealth. 4. Option (B), investment in unproductive activities and purchase of precious stones, jewellery, gold, etc., is also a way black money is often parked or used, representing a misallocation of resources, but not the government's primary fiscal concern. 5. Option (C), large donations to political parties and growth of regionalism, can be facilitated by black money, affecting governance and politics, but the core issue for government finances is different. 6. Option (D), Loss of revenue to the State Exchequer due to tax evasion, is the most direct and significant consequence of black money from the government's perspective. Unreported income means lost tax revenue (income tax, corporate tax, GST, etc.), which hampers public spending, increases deficits, and creates an unfair burden on honest taxpayers. This fiscal impact is the main cause of worry for the government. Therefore, the loss of revenue is the primary concern.