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 sentences comes closest to stating the main idea in this paragraph? (5 points)

a
Yet it is low impact and requires no fancy equipment.
b
That makes walking a simple activity for those new to exercise.
c
Walking is less likely than other exercises to cause injury to leg tendons and muscles.
d
Of course, a person could increase the benefit of a workout by adding weights or speed walking.