Right answer is (b) normalized time

The best I can explain: The normalized time is relative to the time that would be required to convert all the substrate if the enzyme acted at Vmax throughout, the actual time for complete conversion. The equation is given by \(t_n=\frac{t V_{max}}{[S]_0} \).

Fractional conversion is given by X = 1 – S/S0.

Specificity constant is given by Kcat/Km.

Miachelis Menten constant Km is the substrate concentration at which Vmax is reduced to half.