Answer: -
The reaction 6H₂S + 6CO₂ --light--> 6S0 + glucose takes place under anaerobic conditions
Explanation: -
The term anaerobic stands for does not use oxygen.
In the reaction given above
6H₂S + 6CO₂ --light--> 6S0 + glucose
We see that the reactants are hydrogen sulfide and carbon dioxide.
Thus oxygen is not being used in the reaction.
Hence the reaction is occurring under anaerobic conditions.