Choose the One Alternative That Best Completes the Statement or Answers

Multiple Choice

Choose the one alternative that best completes the statement or answers the question.
-The following data represent the infection rate for a particular disease in a third world country x years after a vaccine became widely available. Determine the "best" model to describe the relationship between years past and infection rate.
$\begin{array}{l|l}\text { Years After Vaccine, } x & \text { Infection Rate (\%) , y } \\\hline 1 & 32 \\2 & 11 \\3 & 5 \\4 & 2 \\5 & 0.5\end{array}$

A) exponential model: $\mathrm { y } = 1.955 - 0.435 \mathrm { x }$
B) power model: $\hat { y } = 1.648 - 2.402 x$
C) linear model: $\hat { y } = 31.7 - 7.2 \mathrm { x }$
D) linear model: $\mathrm { y } = 31.7 + 7.2 \mathrm { x }$