Final answer:
a. oxygena. d. carbohydrates. When radiolabeled oxygen is supplied to algae during photosynthesis, the radiolabeled oxygen ends up in oxygen and carbohydrates.
Step-by-step explanation:
When radiolabeled oxygen is supplied to algae during photosynthesis, the radiolabeled oxygen ends up in oxygen and carbohydrates. Oxygen is a byproduct of photosynthesis, released into the atmosphere, while carbohydrates are produced and stored in the cells of the algae. This process occurs in the presence of chlorophyll, which captures the energy from sunlight and drives the photosynthetic reactions.