Which of the following describes a ruminant's digestive process?

A ruminant's digestive process is characterized by the unique means of breaking down food that involves not only stomach digestion but also the action of regurgitating and re-chewing food. This process allows these animals, such as cows and sheep, to efficiently extract nutrients from fibrous plant materials.

Ruminants possess a specialized stomach with four compartments: the rumen, reticulum, omasum, and abomasum. When they initially consume food, it enters the rumen where microbial fermentation occurs—this is crucial for breaking down cellulose found in plant cell walls. After a certain period, the partially digested food, known as "cud," is then regurgitated back into the mouth for re-chewing. This action further breaks down the food particles and mixes them with saliva, which aids in digestion.

The subsequent stomach compartments further process this food, facilitating nutrient absorption primarily in the small intestine, although some absorption also occurs in the large intestine. However, it is not the primary site for nutrient absorption.

Hence, the description of the ruminant's digestive process that highlights regurgitation and re-chewing accurately reflects their complex and specialized method of breaking down food to maximize nutrient absorption from plant material.