Which of the following reaction expresses Van Niel reaction for photosynthesis?

Van Niel, a microbiologist  mile stone contribution was made for photosynthesis. Based on his studies of purple and green bacteria, he demonstrated that photosynthesis is essentially a light-dependent reaction in which hydrogen from a suitable oxidisable compound reduces carbon dioxide to carbohydrates. This can be expressed by: H2A +CO2→Light2A+ CH2O+H2O