Study the given data and answer the questions that follow. A sample of an enzyme called lactase was isolated from the intestinal lining of a calf. Assays were undertaken to evaluate the activity of the enzyme sample. The substrate of lactase is the disaccharide lactose. Lactase breaks a lactose molecule in two, producing a glucose molecule and a galactose molecule. Two assays were carried out. `{:("Lactose concentration (% w/v)",15,15,15,15,15,15),("Concentration of enzyme smaple (%v/v)",0,5,10,15,20,25),("Reaction rate "mu"mole glucose "sec^(-1)mL^(-1),0,25,50,75,100,125):}` `{:("Lactose concentration (% w/v)",0,5,10,15,25,30),("Concentration of enzyme smaple (%v/v)",5,5,5,5,5,5),("Reaction rate "mu"mole glucose "sec^(-1)mL^(-1),0,15,25,35,40,40):}` What are the variables in each of the two assays ?A. `{:(" ""Assay"1," ""Assay"2),("Lactose concentration", "Conentration of enzyme sample"):}B. `{:(" ""Assay"1," ""Assay"2),("Concentration of enzyme sample", "Lactose concentration"):}`C. `{:(" ""Assay"1," ""Assay"2),("Lactose concentration", "Lactose concentration"):}`D. `{:(" ""Assay"1," ""Assay"2),("Conentration of enzyme sample", "Conentration of enzyme sample"):}`