The main difference between photosynthesis and cellular respiration is that photosynthesis is an anabolic process, where the synthesis of organic compounds occurs, storing energy whereas cellular respiration is a catabolic process, where the stored organic compounds are utilized, producing energy.
I think the correct answer would be that soil formation is impaired. It would have not that big of an impact to the society as compared to the other choices. Increase of pest populations would surely affect agriculture. Hindered water purification would affect the quality of groundwater. Also, increasing hole in the ozone surely affect everyone.
