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. Explain whether the main idea is explicit or implicit in this paragraph. (5 points)

a
It is explicit because it is directly stated in the paragraph.
b
It is explicit because it is not directly stated in the paragraph.
c
It is implicit because it is directly stated in the paragraph.
d
It is implicit because it is not directly stated in the paragraph.