6. Walking is not the most exciting form of exercise a person can take on for fitness. Yet it is low impact and requires no fancy equipment. That makes walking a simple activity for those new to exercise. Walking is less likely than other exercises to cause injury to leg tendons and muscles. All it requires is a good pair of sneakers-no cables, stylish outfits, or weights required. Of course, a person could increase the benefit of a workout by adding weights or speed walking.

Which of the following statements supports the main idea in this paragraph? (5 points)

a) Walking is boring.
b) Walking has a low risk of injury.
c) Walking requires sneakers in good condition.
d) Walking is too easy for those who exercise regularly.