Hint: Flagella are hairlike structures which primarily act as an organelle of locomotion in bacteria. Bacterial flagella are helically shaped structures containing the protein flagellin.
The base of this flagella also called the hook which is near the cell surface is attached to the basal body enclosed in the cell envelope. Bacterial flagella rotates in a clockwise or counterclockwise direction, in a motion similar to that of a propeller.
The movement of the prokaryotic flagella depends on the energy derived from the proton-motive force, or ion gradient, across the cell membrane.
Let us analyze the options to find out the correct option.
Option A: The flagella of bacteria is made of a protein called flagellin and has three parts that forms its structure namely basal body, hook and filament. Therefore, this is the correct option.
Option B: Since bacterial flagella is made up of proteins, this is the incorrect option.
Option C: Lipids do not form the flagella of bacteria. It is formed of proteins. Therefore, this is the correct option.
Option D: Carbohydrates do not form bacteria flagellum. It is formed of protein. Therefore, this is the correct option.
Hence, the correct answer is option (A)
Note: Flagella is also present in protozoan group Mastigophora, gametes of algae, fungi, mosses, slime molds, and animals. Flagellar motion causes water currents necessary for respiration and circulation in sponges and coelenterates.