The Ratio of Kcat/Km for Each of Two Different Substrates

Multiple Choice

The ratio of kcat/Km for each of two different substrates present in equal concentrations in an enzyme reaction will measure enzyme affinity because

A) the rates of P formation are given by the values found for each substrate.
B) the rates of P formation are the same for each substrate.
C) it is an indication of the formation of ES for each substrate.
D) All of the above.