Answer:
D
. Unnecessary.
Explanation:
In the study conducted by scientist Daniel, he discovered that people who run without running shoes endure longer and also seem to have lesser foot injuries. His study concluded that man may have been born to be barefoot runners.
Studying people who were raised in the Rift Valley in Kenya, Lieberman found that the people who run barefoot produce long-distance runners. While runners who wear shoes hit the ground with their heels first, barefoot runners do it with their middle or front foot. And this may be why there are fewer foot injuries to them.
Thus, the correct answer is option D.
