(A) Grow plants with CO2
(B) Grow plants without CO2
(C) Grow plants without CO2
(D) Place plants in the dark
Answer: (D) Place plants in the dark
(A) Grow plants with CO2
(B) Grow plants without CO2
(C) Grow plants without CO2
(D) Place plants in the dark
Answer: (D) Place plants in the dark