The term that means of, or relating to horses:

• A. Bovine
• B. Ovine
• C. Galline
• D. Equine

Answer: (D)

Equine denotes anything related to horses. It comes from the Latin equus and is the standard term used in veterinary medicine and animal science to describe horses or horse-related topics, such as equine dentistry or equine anatomy.

Bovine refers to cattle, and ovine refers to sheep, which helps distinguish the species when discussing diseases, care, or anatomy. The term galline is not a standard, widely used English descriptor for chickens; more common terms are avian or poultry. So equine is the precise, widely accepted term for anything pertaining to horses.