The correct option is D Ingenhousz
Photosynthesis is a process by which green plants manufacture their food with the help of carbon dioxide and water in the presence of sunlight. It was discovered by Jan Ingenhousz. Through his experiments, he showed that sunlight is essential for the plant process that helps to somehow purify the air fouled by the breathing mouse and the burning candle in Priestley's bell jar experiment. In another experiment with an aquatic plant (Hydrilla), he showed that in bright sunlight, small bubbles were formed around the green parts of the plant while in dark, no bubbles were formed. He identified those bubbles to be of oxygen. Thus, the correct answer is option C.