A scientist began a study with a sample of 1,500 bacteria. He noticed that the number of bacteria in the sample after t days can be modeled by the equation P=1,500 • 5t . In this equation, what does 5t represent? A. The number of bacteria increases by 5 bacteria each day. B. The number of bacteria increases by a factor of t each day for 5 days. C. The number of bacteria increases by a factor of 5 each day. D. The number of bacteria increases by t bacteria after 5 days.