Respuesta :
the answer is A since oxygen is created and carbon dioxide is taken in during photosynthesis
The statement that best describes what would happen is that carbon dioxide concentration would increase while oxygen concentration would decrease.
The potted plant being placed under the bell jar and sealed off means that it had no access to light for photosynthesis. Thus, the light-dependent reaction of photosynthesis and oxygen production would cease accordingly.
However, respiration would continue because the process is independent of light. This means that any available oxygen within the space of the plant would be utilized for respiration while carbon dioxide would be produced.
Thus, with time, the oxygen level in the jar would dwindle while carbon dioxide level would increase as compared to the classroom air.
More on photosynthesis, respiration, and light can be found here: https://brainly.com/question/9453066