Which of the following is a plant product that the human body cannot digest or absorb?

Roughage is plant food that the human body cannot digest.  It is also called dietary fiber. It largely consists of cellulose. It cannot be digested by our body as our body does not contain cellulose-digesting enzymes. It is important for the growth of beneficial bacteria in the gut and also aids in the movement of undigested food through the intestines.

E.g. whole grains, nuts, seeds, legumes, fruits, and vegetables.