Read the following statements - Assertion (A) and Reason (R):
Assertion: Isoquants are negatively sloped.
Reasoning: With an additional unit of one input, the same level of output can be produced using lesser amount of the other input (when marginal products are positive)
From the given alternatives choose the correct one:

Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).

The correct answer is option 1: Both Assertion (A) and Reason (R) are true and Reason (R) is not the correct explanation of Assertion (A)

Explanation:

1. Assertion (A): Isoquants are negatively sloped. This is true because an isoquant represents different combinations of two inputs that produce the same level of output. If one input increases, the other must decrease to maintain the same output level, resulting in a downward-sloping curve.

2. Reasoning (R): With an additional unit of one input, the same level of output can be produced using a lesser amount of the other input (when marginal products are positive). This is also true because of the principle of input substitutability. If the marginal product of both inputs is positive, increasing one input allows the firm to reduce the other while maintaining the same output.

   The reasoning directly explains why isoquants are negatively sloped. The fact that inputs can be substituted for each other to maintain the same output level is the fundamental reason for the negative slope.