The correct answer is C. Pseudopodia.
Pseudopodia are temporary projections of the cell membrane that are used for locomotion, feeding, and defense. They are formed by the cytoplasm flowing out of the cell and then solidifying. Pseudopodia are found in many types of protists, including amoebas.
Setae are small, hair-like structures that are found on the outside of some animals, such as worms. They are used for locomotion and anchoring the animal to the substrate.
Tube feet are small, tubular projections that are found on the underside of some echinoderms, such as sea stars. They are used for locomotion, feeding, and respiration.
Flame cells are excretory organs that are found in some invertebrates, such as flatworms. They are used to filter waste products from the blood.