Which of the following is not true for the specificity of enzyme action?

• A. Specificity refers to discrimination of an enzyme between two competing substrates
• B. Specificity of enzymes lies both the reaction they catalyze and the substrates on which they act
• C. Specificity makes it possible for a number of enzymes to coexist in the cell without interfering in each other reaction
• D. Five types of specificities have been recognized in enzymes