Friction

In a large commercial complex there are four ways to reach the
main road. One of the path has loose soil, the second is laid with
polished marble, the third is laid with bricks and the fourth has
gravel surface. It is raining heavily and Paheli wishes to reach
the main road. The path on which she is least likely to slip is
(a) loose soil. (c) bricks.
(b) polished marble. (d) gravel.