Final answer:
The correct answer is 'Gait.' A horse's gait refers to the way it moves its legs during progression. Eadweard Muybridge's photography work documented horses' gaits and provided valuable insights into how their legs move.
Step-by-step explanation:
The correct answer is b) Gait.
A horse's gait refers to the way it moves its legs during progression. It is the specific pattern of footfalls and movements that a horse demonstrates when walking, trotting, cantering, or galloping. Different horse breeds and individuals can have different types of gaits. For example, some horses have a smooth, four-beat gait called a running walk, while others have a two-beat gait with a moment of suspension called a gallop.
An example of a study documenting a horse's gait is the work of Eadweard Muybridge. Muybridge used photography to capture sequential images of horses in motion, providing valuable insights into their gaits and how their legs move.