Pick any two points from the table (for example, the first and the last) and calculate the change in $p$ and the change in $n$ between them.

Once you have $\Delta p$ and $\Delta n$, form the ratio $\dfrac{\Delta p}{\Delta n}$ and simplify it. Then see which answer choice is closest to that value.

In Desmos, add a table. Enter the $n$ values (1, 3, 5, 7) in the $x_1$ column and the corresponding $p$ values (3, 7, 11, 15) in the $y_1$ column.

In an empty line, type y1 ~ m x1 + b. Desmos will display values for m and b; m is the slope of the line of best fit. Compare this m value to the answer choices and select the choice closest to it.

For a line (or line of best fit), the slope is the rate of change:

• Slope $=$ change in $p$ divided by change in $n$, often written as $\dfrac{\Delta p}{\Delta n}$.
• You can use any two data points from the table to compute this, especially ones that are far apart.

Pick two points from the table, for example $(1,3)$ and $(7,15)$.

• Change in $n$: $\Delta n = 7-1 = 6$.
• Change in $p$: $\Delta p = 15-3 = 12$.

So the (unsimplified) slope is

Now simplify the fraction from the previous step:

This value is the slope of the line that models $p$ as a function of $n$, so the closest answer choice is $\boxed{2}$.