The correct answer is (a) 18%.
Agriculture is the primary economic activity in many developing countries, and it continues to play an important role in the economies of many developed countries. However, the contribution of agriculture to GDP has been declining in recent years, as other sectors of the economy have grown. In the United States, for example, agriculture accounted for 18% of GDP in 1950, but only 1% of GDP in 2019.
There are a number of reasons for the decline in the contribution of agriculture to GDP. One reason is that productivity in agriculture has increased significantly in recent years. This is due to a number of factors, including the adoption of new technologies, such as improved seeds and fertilizers, and the use of more efficient farming practices. As a result, farmers are able to produce more food with less land and labor.
Another reason for the decline in the contribution of agriculture to GDP is that the demand for agricultural products has been growing more slowly than the overall economy. This is due to a number of factors, including the growth of incomes in developing countries, which has led to a shift in consumption away from basic food items and towards more processed foods.
The decline in the contribution of agriculture to GDP does not mean that agriculture is no longer important. Agriculture still employs a large number of people, and it is a major source of food and fiber for the world. However, it is important to recognize that agriculture is a changing sector, and that its role in the economy is likely to continue to decline in the future.
Option (b), 23%, is incorrect because the contribution of agriculture to GDP is actually much lower than that. Option (c), 25%, is also incorrect for the same reason. Option (d), 28%, is the most incorrect option because it is significantly higher than the actual contribution of agriculture to GDP.