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 and domestic markets with Gain a competitive advantage over similar unsubsidized products. According to the above definition, which of the following is agricultural subsidies? ['The area A is mainly grassland, and the grassland is degraded due to overgrazing. According to the conditions of the area, the national government has issued a subsidy for herders for 8 to 10 years, asking them to reduce the livestock and livestock raised, which has led to higher prices of beef and mutton on the market Up.', "he government of a country matches the farmers and the Rice Research Institute, so that the farmers in the country have planted a new variety of rice. The quality and yield of this type of rice have been greatly improved, making the country's rice export prices almost the same as those on the international market.", "n order to stabilize the price of agricultural products, in addition to the reduction and exemption policy for stall rents of farmers' market operators, a city government also stipulates that if the rents of stalls are lower than the specified amount, subsidies ranging from 10% to 40% can be issued to operators.", 'In-country D, the government bought corn grown by farmers at a price higher than the international market, and sold it at a low price to encourage farmers to plant corn. A company in the country used corn as the main feed to cultivate broiler chickens, and then exported it to country B in large quantities.']