I agree: a capped soda bottle has very limited contact with the surroundings, as it has to be relatively closed so that the gas bubbles don't escape.
The remaining options have contact either with air (A and D) or with water from the outside (B)
The answer to your question is A. You are correct
I think it’s A, the number of electrons equals the protons in a neutral atom
The pollution from the Industrial Revolution darkening the trees. After the trees darkened from all the soot in the air, the white moths were easier to see and more vulnerable to predators. The dark moths blended into the dark tree bark.
