Final answer:
The minimum size of a dirt pocket drop can be 1-5 inches or 8 inches.
Thus, the correct option is b.
Step-by-step explanation:
The minimum size of a dirt pocket drop can vary depending on the context. In the first reference, it suggests that a newer work suggests as much as 8 diameters side-to-side and 15 diameters deep, which means the minimum size would be 8 inches in diameter.
However, another reference mentions that the answer is 1-5 inches and w=3 inches. So, based on the given information, the minimum size of a dirt pocket drop can be either 1-5 inches or 8 inches.
Therefore, the correct option is b) 8 inches.