The correct answer is option B- Flagella
Flagella are a microscopic, whip like structure attached to cells of protozoan, bacteria and help them swim.
There are 4 ways flagella can be attached to a cell.
- A single whip at one end of cell called Monotrichous
- A bunch of flagella at one end is called Lophotrichous
- A Pattern in which Flagella cover the whole cell is called Peritrichous
- Bacterial cell without flagella is called Atrihous