In a drug design scenario, why might a small Km be desirable for a therapeutic enzyme?

• A. A small Km indicates low affinity, requiring high substrate concentrations for effectiveness.
• B. A small Km indicates high affinity, allowing the enzyme to be effective at low substrate concentrations.
• C. A small Km suggests the enzyme is unstable and unsuitable for therapy.
• D. A small Km means the enzyme is inactive, making it a poor therapeutic choice.

Answer: (B)