Respuesta :
Well active transport absolutely moves substances against their concentration gradient (answer C), although I dislike how the other answers could probably be argued for.
Answer:
Active transport moves substances against the concentration gradient.
Explanation:
Because the transport it against the gradient, it required energy. Various nutrients like amino acids, monosaccharides like glucose, electrolytes like Na+ are absorbed into the blood from intestine by active transport mechanism only.
When the transport of molecules is along the gradient it is referred as passive transport. However some of the substances are absorbed with the help of a carrier ion or molecule. Such mechanism is called facilitated transport.