Solution:

When a cyclist takes a zig-zag path, the effective angle of inclination \( \alpha \) becomes smaller than the actual angle \( \theta \). This reduces the component of gravity along the slope \( mg \sin \alpha \) and increases the normal force \( mg \cos \alpha \). This makes it easier to ascend and helps prevent slipping. Both (A) and (R) are true and (R) is the correct explanation of (A).