Answer:
The correct answer is number one: Filamentous rotating structures that provide motility may be singular, paired or scattered.
Step-by-step explanation:
Flagella are organelles defined by function rather than structure.
The primary function is that of locomotion but also being sensitive to chemicals and temperatures outside the cell.
Helicobacter pylori is a good example of flagella: It uses multiple flagella to propel itself through the mucus lining to reach the stomach epithelium.
Sperm cell is a good example, which uses its flagellum to propel itself through the reproductive tract of females.
I hope it helps!