Robert, a Baker, Receives an Order for Preparing 10 Cakes

Robert, a baker, receives an order for preparing 10 cakes in one day. He is given a budget of $5,000. In six hours, he bakes two-thirds of the order and spends $3,600. Calculate the schedule performance index from the given scenario.

A) 0.55
B) 0.33
C) 0.25
D) 0.66
E) 0.75