Answer:
B) They would produce less pollen
Step-by-step explanation:
The reason why A would be incorrect is because green houses still have sunlight!! During the steps of photosynthesis: first they have to absorb the sunlight, second, electrons transport leading to the reduction of NADP+ to NADPH, third, they convert that into ATP, and fourth, they convert the ATP of CO2 into carbohydrates. The rest are pretty self explanatory on why it would be wrong, due to them not really making sense.
IF THAT'S NOT CORRECT THE ANSWER WOULD BE THEY STOP PRODUCING FLOWERS DUE TO THE EXPLANATION OF THE OTHER USER!!!