Two vials with bromothymol blue and a snail!?

Question

....Are left for 24 hours, one in the light, and one in the dark. The color changes from blue to green or yellow in both vials because the snail:

A. uses oxygen from the solution

B. uses carbon dioxide from the solution

C. releases oxygen into the solution

D. releases carbon dioxide into the solution

Answer 1

D. releases carbon dioxide into the solution - during respiration.