The correct answer is "procurement prices."

Procurement prices refer to the prices at which the government purchases food grains from farmers to support various initiatives such as maintaining the public distribution system (PDS) and building up buffer stocks. These prices are determined by the government and are typically higher than the market prices to provide farmers with a guaranteed minimum income and incentivize agricultural production. The government procures food grains directly from farmers at these prices to ensure an adequate supply for distribution through the PDS and to maintain buffer stocks for food security purposes.