Answer: I think it’s the first one
Based on the liquids viscosity (which is a measure of how quickly/slowly a fluid can flow).
Higher viscosity represents a "thicker" liquid & slower flow (honey)
Lower viscosity represents a "thinner" liquid & quicker flow (vinegar)
Equation: MgOH2 (s) --> MgO (s) + H2O (g)
And it's already balanced.
I had chemistry this semester too.