We have a formula for the speed v in function of s, the distance between footsteps of the same foot, and f, the length of the foot:
We can calculate v when s = 1 m and f = 0.65 m by replacing this variables with their values and solving the expression:
Given the options, it corresponds to v = 0.26 m/s.
Answer: About 0.26 m/s [Fourth option]