Why is the steady state assumption crucial for deriving the Michaelis constant (Km) and the Michaelis-Menten equation?

• A. It assumes that the substrate concentration is always higher than the enzyme concentration.
• B. It assumes that the enzyme concentration is always higher than the substrate concentration.
• C. It assumes that the product concentration is negligible.
• D. It allows the simplification of complex kinetic equations by assuming constant enzyme-substrate complex concentration.

Answer: (D)