Bacterial degradation of cellulose and fermentation of glucose occur in the rumen of cows, sheep and other ruminant animals. The main source of energy for the fermenters is , while the main source of energy for the ruminant is

Glucose, volatile fatty acids

Explanation:

Fermentation involves breaking down of carbohydrate anaerobically with the help of microbes. These microbes require glucose to work . The source of energy of ruminants as the volatile fatty acids which is a product of digestion and amounts to about 70percent of its energy source. The availability of this volatile fatty acids determine the fat and protein composition of the milk.

i am positive it is c. condensing but i may be wrong