In which year was Dattopant Thengadi National Board for Workers Education and Development established?

The correct answer is 1958.

Step-by-step Explanation:
1. The Dattopant Thengadi National Board for Workers Education and Development (DTNBWED), previously known as the Central Board for Workers Education (CBWE), is an autonomous body under the Ministry of Labour and Employment, Government of India.
2. It was formally established in 1958 (on September 16, 1958) during the Second Five-Year Plan to carry out workers' education schemes and build awareness among workers regarding their rights, responsibilities, and leadership in trade unions.
3. It was later renamed to honor Dattopant Thengadi, a prominent trade unionist, social reformer, and founder of the Bharatiya Mazdoor Sangh (BMS).