The rate of photosynthesis can be determined by measuring the rate that reactants are used up by a plant or by measuring the rate that products of photosynthesis are produced by a plant. How would placing a plant in a dark room for 24 hours affect the rate of photosynthesis? Ⓐ The rate of photosynthesis would increase and the plant would take in more water. Ⓑ The rate of photosynthesis would decrease and the plant would produce more sugar. Ⓒ The rate of photosynthesis would increase and the plant would produce more oxygen. Ⓓ The rate of photosynthesis would decrease and the plant would take in less carbon dioxide.