The question is asking for a classification of an activity, and the correct answer is "locomotor." Locomotor activities involve movement from one place to another, such as walking, running, or jumping. Non-locomotor activities, on the other hand, are stationary movements that do not involve traveling, such as stretching or bending. Since the question specifically mentions "walking," which is a type of locomotor activity, it can be inferred that the correct answer is "locomotor."