Which of the following best describes a carnivore's digestive system?

A carnivore's digestive system is characterized by a relatively simple stomach and short intestines. This anatomical structure is well-suited for their dietary needs, as carnivores primarily consume animal protein and fat, which are easier to digest than plant materials. The simple stomach allows for efficient protein breakdown, while the shorter intestines facilitate quicker passage of the highly digestible food, reducing the time necessary for digestion and absorption.

The other choices describe characteristics more aligned with herbivores or ruminants. For example, complex digestion with a rumen refers to the multi-chambered stomach typical of ruminants, such as cows, which are adapted to break down tough plant cell walls through fermentation. Similarly, adaptations for rapidly digesting plant material and having a long alimentary canal with multiple chambers are also features commonly seen in herbivorous species, which require more time and specialized structures to efficiently process plant-based diets. In contrast, carnivores thrive on a diet that allows for swift digestion and absorption, justifying the correct option regarding their digestive anatomy.