Pick two labeled points on the line and compute the slope using $\frac{\Delta y}{\Delta x}$.

Choose the equation whose slope matches your computed slope and whose constant term matches the $y$-intercept.

In Desmos, type the two points shown on the line: (4,110) and (14,260).

Type (260-110)/(14-4) and note the value Desmos gives for the slope.

From the graph, note the $y$-intercept (where $x=0$). Combine your slope and intercept to form an equation of the form $y=mx+b$, then select the matching choice.

The $y$-intercept is where the line crosses the $y$-axis ($x=0$).

From the graph, the line crosses the $y$-axis at $y=50$, so the equation has the form $y=mx+50$.

Two labeled points on the line are $(4,110)$ and $(14,260)$.

Compute the slope:

Substitute $m=15$ and the intercept 50: