Biology

The correct answer is: C.Active Transport  

Explanation:

Molecules move through a protein from the lower side to the higher side, requiring ATP. This is a typical characteristic of active transport, where molecules move against their concentration gradient (from low concentration to high concentration), which requires ATP to provide energy for the process.

Why the other options are incorrect:

A.Endocytosis: This is a type of bulk transport where the cell engulfs large particles or liquids by wrapping the cell membrane around them and forming vesicles. This is not about moving molecules against a gradient using a protein.