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?

Black money refers to income that is not disclosed to tax authorities and on which taxes are not paid. While all the given options are indeed consequences of black money, the core problem and the primary concern for the government from a fiscal and governance perspective is the loss of revenue.

Options A, B, and C describe ways in which black money is used or its broader societal implications (diversion to unproductive assets, speculative investments, funding political parties). However, these are secondary effects that stem from the initial act of generating and concealing income to evade taxes. The most direct and significant impact on the government's ability to function and provide public services is the loss of tax revenue. This directly impacts the government's budget, its capacity to finance development projects, and its overall fiscal health.

Therefore, the loss of revenue to the State Exchequer due to tax evasion is the main cause of worry to the Government of India.