answer is : b. the universe ♡
The substance that would be added in order to reverse the reaction would be any substance that is found in the product side. Adding a substance that tends to be a product will shift the equilibrium of the system and will allow the reaction to produce the substances that is found in the reactant side.
Explanation:
Plasma
White blood cells
Red blood cells
from top to base of test tube
Guard cells are located in the leaf epidermis and pairs of guard cells surround and form stomatal pores, which regulate CO2 influx from the atmosphere into the leaves for photosynthetic carbon fixation.
Stomatal guard cells also regulate water loss of plants via transpiration to the atmosphere.