The correct answer is None. Explanation & Key Takeaways: • four decades of economic planning • The statement suggests that during the first four decades of economic planning, reliance on commodity taxation increased. • While the specific time period and country aren't mentioned, it is generally true that many countries have increased their reliance on commodity taxation during their early stages of economic planning and development. • Commodity taxation refers to taxes levied on goods and services, such as sales taxes, excise taxes, and value-added taxes (VAT). • tax revenue of the central government in 1990-91 • In India, during the early 1990s, the tax system was predominantly based on indirect taxes, such as commodity taxation. • This included customs duties, excise duties, and sales taxes. • In 1991, India introduced economic liberalization policies, which marked a shift in the country's economic planning. • These reforms aimed to reduce the fiscal deficit, improve tax compliance, and simplify the tax system.