Question 1: im not completely sure but either A or B. but i would go with A
question 2: B-calvin cycle
question3: B-splitting carbon dioxide.
question 4: B-chlorophyll
Answer:
Explanation:
Green crabs have chemoreceptors located on an <em>antenna</em>.
These are long segmented appendages near the crab´s eyes that have both chemoreceptors and allow them to feel the surroundings.
Crabs also have antennules, like short appendages close to the antennas that allow them to <em>sense</em> their environment. A crab can "taste" using hairs on their mouthparts, pincers and even its feet.
So they can detect the salinity of the water by "taste" using the antennules. If these antennules are bathed with nonsalty water, the information the crab´s brain receives is to increase the salinity of its body by the system explained above, increasing its rate of urine production.
I hope it helps!
Variables is likely the correct answer.
