What type of transport requires energy to move sodium ions from a low concentration across the intestinal wall into a higher concentration? a) diffusion b) active transport c) osmosis d) passive transport

Active Transport is the answer

The correct answer is option B, that is, active transport.

Explanation:

In order to move a substance against an electrochemical gradient or concentration gradient, a cell needs energy. Thus, for this a cell follows active transport mechanisms, for this, energy is expended in the form of ATP in order to sustain the appropriate concentrations of molecules and ions in the living cells.  

The active transport refers to the phenomenon in which the movement of molecules or ions takes place through a cell membrane from the region of lower concentration to a region of a higher concentration, facilitated by the enzymes and the process requires energy in the form of ATP.  

because it travels in smaller waves then all other colors, causing it to be the most visible color