A statistician observed the health systems of several countries. She identified a few statistical associations and modeled them: Function | Input | Output - | - | - $C$ | Average daily consumption of cigarettes per person, $x$ | Number of sick people out of $1000$, $C(x)$ $S$ | Number of sick people out of $1000$, $k$ | The country's health expenses per person, $S(k)$ $P$| The country's health expenses per person, $r$ | The price of basic health insurance, $P(r)$ **According to the statistician's findings, which of the following represents the price of basic health insurance as a function of the number of sick people?** [[☃ radio 1]]