Which of These Is an Incorrect Comparison Between Flagella and Cilia

Which of these is an incorrect comparison between flagella and cilia?

A) Flagella have essentially the same internal structure of cytoskeleton proteins as cilia.
B) Flagella are used for propulsion, while cilia are used to attach cells to other cells or surfaces.
C) Flagella are found in all three domains of organisms, while cilia are found only in Eukarya.
D) Flagella are longer structures than cilia.