the answer is c. hydrogen bonding
Green plants and trees use photosynthesis to make food from sunlight, carbon dioxide and water in the atmosphere: It is their primary source of energy. The importance of photosynthesis in our life is the oxygen it produces. Without photosynthesis there would be little to no oxygen on the planet.
Has something to do with science
Dr. Strayer is most likely a social psychologist. Social psychology deals with interactions between people within in group and group behavior. Social psychology is scientific discipline that deals with social behavior of people or interactions between people in social groups.