When the Vmax and the Km of an enzyme are not known, it is essential to determine the enzyme's initial velocity (Vo) at different [S]. To determine the initial velocity, one would have to: Select one: a. Use the Michaelis Menten equation b. Measure the amount of product formed after the reaction has reached equilibrium c. Measure the change of [P] vs time in the initial, linear phase of the experiment d. Find the substrate concentration that gives half the Vmax e. Search the internet for this enzyme's Vo values