Use the Following Information to Answer the Questions Below

Multiple Choice

Use the following information to answer the questions below.
You have learned about research conducted during the 1930s by van Niel, who studied photosynthesis in bacteria, which were observed to not release O₂ even though they fixed CO₂.
-These organisms were confounding because the prevailing hypothesis at that time was that

A) autotrophs released O₂ from the splitting of CO₂ to make sugars.
B) autotrophs didn't use CO₂.
C) CO₂ was released and oxygen used up during photosynthesis.
D) only heterotrophs released O₂ while fixing carbon.
E) the process of photosynthesis was unknown at this time.