The development and diffusion of high yield varieties of food crops.Group of answer choicesMalthusianismIntensive agricultureGreen RevolutionSubsistence agriculture

The answer is Green Revolution. The Green Revolution refers to a series of research, development, and technology transfer initiatives, occurring between the 1940s and the late 1970s, that increased agricultural production worldwide, particularly in the developing world, beginning most markedly in the late 1960s. The initiatives involved the development of high-yielding varieties of cereal grains, expansion of irrigation infrastructure, modernization of management techniques, distribution of hybridized seeds, synthetic fertilizers, and pesticides to farmers.

The development and diffusion of high yield varieties of food crops is most closely associated with the Green Revolution.

Here's a step-by-step explanation:

1. Malthusianism is a theory proposed by Thomas Robert Malthus suggesting that population growth will outpace agricultural production, leading to famine and disease. This doesn't directly relate to the development and diffusion of high yield varieties of food crops.

2. Intensive agriculture refers to a type of agriculture, both of crop plants and of animals, with higher levels of input and output per cubic unit of agricultural land area. It is characterized by a low fallow ratio, higher use of inputs such as capital and labour, and higher crop yields per unit land area. This doesn't specifically refer to the development and diffusion of high yield varieties of food crops.

3. The Green Revolution refers to a series of research, development, and technology transfer initiatives, occurring between the 1940s and the late 1970s. It increased agricultural production worldwide, particularly in the developing world, by the development of high-yielding varieties of cereal grains, expansion of irrigation infrastructure, modernization of management techniques, distribution of hybridized seeds, synthetic fertilizers, and pesticides to farmers. This is the correct answer.

4. Subsistence agriculture is a self-sufficiency farming system in which the farmers focus on growing enough food to feed themselves and their families. This type of agriculture does not involve the development and diffusion of high yield varieties of food crops on a large scale.