With reference to the Liberalized Exchange Rate Management System (LERMS), consider the following statements:

1. Following the recommendations of the C. Rangarajan Committee it was implemented with the dual exchange rate.

2. The Reserve Bank of India (RBI) purchased 75 per cent of the proceeds of exports and inward remittances at the official exchange rate for official use under this scheme.

3. Essential materials or products, such as petroleum, fertilizers, and life-saving pharmaceuticals, were imported using foreign exchange and surrendered at the official rate.

4. Authorized dealers are no longer required to sell any percentage of their foreign currency receipts directly to the Reserve Bank, as was formerly the case.

Which of the statements given above are correct?