In animals, digestion functions as a mechanism for a. converting carbon dioxide into oxygen b. converting oxygen into atp c. breaking down food into small molecules d. breaking down glucose into atp

its c

Explanation:

because i said so if thats not enough

food; continues with its mastication (chewing), insalivation (mixing with the salivary secretions), degluti-tion (swallowing), and the digestion, absorption, and assimilation of those food elements that are of nutritive value

Land use goes up as human population goes up. This is because the more people there are alive, the more land that people will be using. Hope this helps :)