When atmospheric oxygen levels began to rise, there was an increase in aerobic organisms. question options: true false

True. When oxygen increases, an increase in aerobic organisms also occurs. The increase in atmospheric oxygen favors the appearance of these organisms. The increase in atmospheric oxygen favors the appearance of aerobic organisms. There are several consequences in the evolution of organisms that could use oxygen as the plants that are the main factories of oxygen in the earth and depend on atmospheric CO2 (photosynthesis).

Why you put last one a? i think is b.