Covering of the Bryophytes is called the pellicle. The pellicle is a thin layer supporting the cell membrane in various protozoa such as ciliates, protecting them and allowing them to retain their shape, especially during locomotion, allowing the organism to be more hydrodynamic. They vary from flexible and elastic to rigid. Although somewhat stiff, the pellicle is also flexible and allows the protist to fit into tighter spaces. Hence the correct option is B.