3. which is true about the light-independent reactions?
a. no carbon dioxide because it was used up in the light-dependent reactions.
b. energy-rich carbohydrates are all used up, allowing none to leave the cycle.
c. carbon dioxide is broken off of molecules with three carbons.
d. energy taken from atp and nadph is used to make energy-rich carbohydrates.

the correct choice is d

Energy taken from ATP and NADPH is used to make energy-rich carbohydrates.The light-independent reactions are reactions in which ATP and NADPH is used for the conversion of carbon dioxide into energy-rich carbohydrates. So, the carbohydrates are produced and not used up as stated in choice B. Carbon dioxide is neither broken off of molecules with three carbons nor were used up in the light-dependent reactions, leaving choices a. and b. as wrong ones.