At the point of inflexion, the marginal product is

Increasing
Decreasing
Maximum
Negative

The correct answer is: C. Maximum

The marginal product of an input is the additional output produced by using one more unit of that input. The point of inflexion is the point on a graph where the slope of the curve changes from increasing to decreasing. At the point of inflexion, the marginal product is at its maximum.

Here is a diagram to illustrate:

[Diagram of a graph with a curve that starts increasing, reaches a point of inflexion, and then starts decreasing]

The point of inflexion is the point where the curve changes from concave up to concave down. This is the point where the marginal product is at its maximum.

Here is a brief explanation of each option:

  • Option A: Increasing. The marginal product is increasing when the slope of the curve is positive. This is the case before the point of inflexion.
  • Option B: Decreasing. The marginal product is decreasing when the slope of the curve is negative. This is the case after the point of inflexion.
  • Option C: Maximum. The marginal product is at its maximum when the slope of the curve is zero. This is the case at the point of inflexion.
  • Option D: Negative. The marginal product is negative when the output produced by using one more unit of the input is less than the output produced by using the previous unit of the input. This is not the case at the point of inflexion.