Agricultural subsidies usually refer to the financial or financial support provided by the government of a country's agricultural product producers or operators, including cash subsidies, price support or other preferential policies to make its agricultural products in the international, domestic market and Gain a competitive advantage over similar subsidized products. According to the above definition, which of the following is agricultural subsidies? ["In order to stabilize the price of agricultural products, in addition to the reduction and exemption policy of the stall rent of the farmers' market operators, a city government also stipulates that if the stall rent is lower than the specified amount, the operator can be granted a subsidy ranging from 10% to 40%.", 'In the market of country A. the government purchases corn grown by farmers at a price higher than the international market and sells it at a low price to encourage farmers to plant corn. A company in the country uses corn as the main feed to cultivate broiler chickens and then exports it to country B in large quantities.', 'Area A is mainly grassland, and the grassland is degraded due to overgrazing. According to the situation in the area, the national government grants herders 8 to 10 years of subsidies and asks them to reduce the livestock and livestock raised, which leads to higher prices of beef and lamb in the market Up.', "The government of a country matches the farmers and the Rice Research Institute so that farmers in the country plant new varieties of rice. The quality and yield of this type of rice has been greatly improved, making the country's rice export prices almost the same as those on the international market."]