White from coronet to mid cannon is known as a _______ leg marking.

The correct answer refers to a specific type of leg marking in horses, where the white marking extends from just above the hoof at the coronet band to the midpoint of the cannon bone. This type of marking is referred to as a "Half Stocking."

A "Half Stocking" is characterized by its coverage, which is distinctly less than a full stocking, where the marking would extend all the way up to the carpus or hock. The distinction is important in horse evaluation, as leg markings can impact a horse's conformation and breed standards.

The other terms listed, such as "Full Stocking," "Pastern," and "Ankle," refer to different divisions of leg markings. A "Full Stocking" would cover the entire leg from the coronet to above the knee or hock, while a "Pastern" marking is limited to the area above the hoof and just below the fetlock. The term "Ankle" usually refers to the area closer to the joint but does not specifically describe a marking. Therefore, the designation of a marking extending from the coronet to mid-cannon as a "Half Stocking" is accurate and aligns with the established terminology used in horse evaluations.