When solving the question, shall we take p(partial pressure) or c(concentration) ?

Biodiesel, fatty acid methyl ester (FAME) is a renewable, biodegradable alternative fuel made through a chemical reaction of triglyceride (T) and methanol (M) on the solid catalyst. The mechanism of this reaction is shown below: Derive a rate law assuming triglyceride and methanol are adsorbed on different sites as shown below. Consider that FAME is not adsorbed on the solid catalyst and the surface reaction is rate-limiting step. Hint: Start by completing the reaction mechanism