Which of the following explains correctly, the rate of photosynthesis in some plants follows a 24-hour cycle even if light and other environmental factors are constant?

Plant circadian rhythms tell the plant what season it is and when to flower for the best chance of attracting pollinators. Behaviours showing rhythms include leaf movement, growth, germination, stomatal/gas exchange, enzyme activity, photosynthetic activity, and fragrance emission, among others. Circadian rhythms occur as a plant entrains to synchronize with the light cycle of its surrounding environment. These rhythms are endogenously generated and self-sustaining and are relatively constant over a range of ambient temperatures.
So, the correct answer is option B.