A scientist began a study with a sample of 450 bacteria. He noticed that the number of bacteria in the sample after t days can be modeled by the equation P = 450(4)t. In this equation, what does 4t represent?

A.
The number of bacteria increases by 4 bacteria each day.

B.
The number of bacteria increases by a factor of 4 each day.

C.
The number of bacteria decreases by 4 bacteria each day.

D.
The number of bacteria increases by t bacteria after 4 days.