The answer is B. Canine.
Canines are pointed teeth that are used for tearing and piercing food. They are found in carnivores and omnivores, but not in herbivores. Herbivores do not need canine teeth because they do not eat meat. They eat plants, which can be easily chewed with incisors and molars.
Incisors are the front teeth that are used for cutting food. They are found in all mammals, including herbivores. Molars are the back teeth that are used for grinding food. They are also found in all mammals, including herbivores. Premolars are teeth that are located between the canines and molars. They are used for both cutting and grinding food.
Herbivores have a variety of adaptations that help them to eat plants. Their teeth are designed for grinding tough plant material, and their digestive system is able to extract nutrients from plants that carnivores and omnivores cannot.