Answer:
a. It's a carrier protein doing facillitated diffusion
Explanation:
Facilitated diffusion may be defined as the transportation of molecules from a high concentration to a low concentration that is down the concentration gradient without input of the energy. Whereas the active transport is transportation of the molecules from the low concentration to the high concentration which is against concentration gradient by the membrane protein.
The glucose transportation process requires membrane protein for the transport and does not require any energy. Therefore, it is carrier protein which is doing the facilitated diffusion.
Homeostasis is the maintenance of a stable level of internal conditions even though environmental conditions are constantly changing. Metabolism is the sum of all the chemical reactions that take in and transform energy and materials from the environment.
I believe the best answer is C.