At what substrate concentration would the enzyme operate at one-sixth of its maximum velocity, given it has a kcat of 345s−1 and a KM of 0.45×10−3 M according to Michaelis-Menten kinetics?
A) 0.075×10−3M
B) 0.45×10 −3M
C) 2.70×10 −3M
D) 1.80×10 −3 M