How Does a High Environmental PH Affect an Enzyme's Activity

How does a high environmental pH affect an enzyme's activity?

A) High pH decreases the activity of all enzymes.
B) High pH increases the activity of all enzymes.
C) High pH changes the shape of all enzymes.
D) High pH does not affect the enzyme, but does lower the availability of substrate.
E) Some enzymes work well at a high pH, some work well at low pH.