Exponential Growth Model Initial Value Problem

The number of bacteria in a culture is modeled by a differentiable function $N$, where $N(t)$ is the number of bacteria in thousands and $t$ is the time in hours. The population grows according to the differential equation $\frac{dN}{dt} = kN$, where $k$ is a constant. At time $t=0$, there are 150 thousand bacteria, and the population is increasing at a rate of 45 thousand per hour. Which of the following gives an expression for $N(t)$?