Explanation:

Liquidity Adjustment Facility (LAF) is a monetary policy tool of Reserve Bank of India for modulating liquidity and transmitting interest rate signals to the market. It is used to aid banks in adjusting the day to day mismatches in liquidity. The two components of LAF are repo rate and reverse repo rate. Under Repo, the banks borrow money from RBI to meet short term needs by putting government securities as collateral. Under Reverse Repo, RBI borrows money from banks by lending securities.
• Other than Regional Rural Banks, all the Scheduled Commercial Banks are eligible to participate in auctions. Primary Dealers (PDs) and NBFCs are also eligible to participate in auctions.
• Primary dealers are registered entities with the RBI who have the license to purchase and sell government securities. They are entities who buy the government securities directly from the RBI (the RBI issues government securities on behalf of the government), aiming to resell them to other buyers.
• Hence (d) is the correct answer.