The diagram below represents a production function. At which of the points does diminishing returns set in __________

Diminishing returns set in at point T in the production function. In a production function, adding more units of input (such as labor or capital) typically leads to an increase in output at a certain rate. However, as the amount of input increases beyond a certain point, the rate of output increase begins to decline. This is known as the law of diminishing returns. In the diagram, points R and S represent the increasing phase of the production function where output increases at an increasing rate as more input is added. However, at point T, the rate of increase in output begins to slow down, indicating that the law of diminishing returns has set in. Beyond point T, adding more input will result in smaller increases in output, and may even cause a decrease in output if the input becomes too excessive, as shown by point V. Therefore, point T is where diminishing returns set in, indicating the optimal level of input for maximum output.