Consider a Sample of Water in a Closed Container

Multiple Choice

Consider a sample of water in a closed container. When the reaction H₂O(l) H₂O(g)
Has reached equilibrium, what can we say about any specific water molecule?

A) If it was present in the liquid it will always remain in the liquid.
B) If it was present in the gas it will always remain in the gas.
C) It will sometimes be in the liquid phase and sometimes in the gas phase.
D) Both a and b are true.