According to "Universal Soil Loss Equation" the factors on which ration of erosion depend are :

Question

$\begin{array}{1 1} (a)\; \text{Rainfall, soil credibility and slope} \\ (b)\; \text{Rainfall, soil credibility, slope length, soil gradient, crop management, erosion control practice} \\ (c)\; \text{Rainfall, wind velocity, crop management} \\ (d)\; \text{Soil credibility, soil type, crop management} \end{array}$