SAT Math Practice Question

Keith modeled the growth over several hundred years of a tree population by estimating the number of the trees' pollen grains per square centimeter that were deposited each year within layers of a lake's sediment. He estimated there were 310 pollen grains per square centimeter the first year the grains were deposited, with a $1 \%$ annual increase in the number of grains per square centimeter thereafter. Which of the following functions models $P(t)$, the number of pollen grains per square centimeter $t$ years after the first year the grains were deposited?

1. A.$P(t)=310^{t}$
2. B.$P(t)=310^{1.01 t}$
3. C.$P(t)=310(0.99)^{t}$
4. D.$P(t)=310(1.01)^{t}$