Correct option is A
The Universal Soil Loss Equation (USLE) is expressed as:
A = R × K × L × S × C × P,
where A = predicted soil loss, R = rainfall erosivity, K = soil erodibility, L = slope length, S = slope steepness, C = cover management, and P = support practices.
The reason correctly explains the use of this equation to guide cropping and conservation practices for reducing erosion. Hence, both A and R are true, and R is the correct explanation of A.