The Total Number $N$ Of Bacteria Cells in a Petri Dish When Exposed to Dish

Multiple Choice

The total number $N$ of bacteria cells in a petri dish when exposed to a new drug can be approximated by the function $\mathrm{N}(\mathrm{x}) =75 \mathrm{e}^{-0.02532 \mathrm{x}}$ , where $\mathrm{N}$ is measured in thousands; and $\mathrm{x}=0$ corresponds to the initial number of cells, $\mathrm{x}=1$ corresponds to the number of cells after one hour, and so on. The function is graphed on a graphing calculator-generated screen. Interpret the meanings of $x$ and $y$ in the display at the bottom of the screen.

A) It means that the drug is helping the bacteria grow.
B) It means that after 75 hours, there will be approximately 45,200 bacteria cells.
C) It means that after 20 hours, there will be approximately 45,200 bacteria cells.
D) It means that after 20 hours, there will be approximately 45 bacteria cells.