While studying enzyme kinetics in the lab, a scientist observed that the rate...

While studying enzyme kinetics in the lab, a scientist observed that the rate of a reaction involving enzyme amylase increased as the concentration of starch increased. With further increase in starch concentration, the amylase activity did not change. Why did this happen?
A. The starch molecules did not bind to the enzyme amylase efficiently.
B. The enzyme amylase was saturated, as all its active sites were occupied by substrate starch.
C. The starch molecules were converted to product glucose as soon as they bound to enzyme amylase.