The by-product in plant photosynthesis is? by Sunday | Jun 8 | Agricultural Science WAEC | 0 comments A. carbondioxide B. carbohydrate C. hydrogen D. oxygen Correct Answer: Option D – oxygen Users Also Read These:The first stable product of photosynthesis is?Which of the following is considered to be the first…Which of the following is considered to be the first…The difference between the gross domestic product…The first stable product of photosynthesis is?