The correct answer is (c) 5 years.
The Finance Commission is a constitutional body constituted every five years to review the financial relations between the Union and the States and to make recommendations to the President on the distribution of revenues between the Union and the States, the principles governing grants-in-aid to the States, and the measures needed to augment the Consolidated Fund of India.
The Finance Commission was first constituted in 1951. The current Finance Commission is the 15th Finance Commission, which was constituted in 2020. The 15th Finance Commission is headed by N. K. Singh.
The Finance Commission plays a vital role in the Indian federal system. Its recommendations have a significant impact on the finances of the Union and the States. The Finance Commission is a highly respected institution, and its recommendations are generally accepted by the Union and the States.