$\begin{array}{1 1} (a)\; \text{Human beings do not have cellulose-digesting enzymes} \\ (b)\; \text{Cellulose gets absorbed in the human blood and converts into fibres } \\ (c)\; \text{The cellulose-digesting bacteria convert cellulose into fibres} \\ (d)\; \text{Cellulose breaks down into smaller components which are egested as roughage} \end{array}$
