How do the light and dark reactions work together?
a. the dark reactions provide energy carriers for the light reactions.
b. the light reactions provide photons for the dark reactions.
c. the dark reactions provide photons for the light reactions.
d. the light reactions provide energy carriers for the dark reactions.

The light reaction provides the dark reaction with nutrients, which is ATP.

In short, the answer is D:

The light reactions provide energy carriers for the dark reactions.

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.