SAT Question 16889ef3: Linear Functions answer and explanation with Desmos solution

Choice C is correct. It is assumed that the oil and gas production decreased at a constant rate. Therefore, the function $f$ that best models the production $t$ years after the year $2000$ can be written as a linear function, $f(t)=mt+b$, where $m$ is the rate of change of the oil and gas production and $b$ is the oil and gas production, in millions of barrels, in the year $2000$. Since there were $4$ million barrels of oil and gas produced in $2000$, $b=4$. The rate of change, $m$, can be calculated as $\frac{4-1.9}{0-13}=-\frac{2.1}{13}$, which is equivalent to $-\frac{21}{130}$, the rate of change in choice C.