While testing amylase activity, John uses a buffer of pH 6 and substrate starch. He incubates them at 104ºF (40ºC). All the tubes show glucose formation, except one, which had no starch solution. Why did this happen?

AThe optimum pH for the enzyme amylase is not pH 6.

BThe optimum temperature for the enzyme amylase is not 104°F (40°C)

CThe substrate for amylase, starch, is not present.