You are presented with the question "Vesicle transport requires energy and a what?" and the following answer choices: 
- activity
 - major threat to health
 - metabolic reaction
 - hydration
 - biofuel
 - wavelengths and photons
 - carrier molecule
 - Vibrations.

Now knowing that vesicle transport requires energy, so it is also a form of active transport and active transport requires a carrier molecule and a form of energy, choose the best answer.


 

       carrier molecule  