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.
-In a Psychology class, the students were tested at the end of the course on a final exam. Then they were retested with an equivalent test at subsequent time intervals. Their average scores after t months are given in the table.
$\begin{array}{l|ccccc}\text { Time, } \text { (in months) } & 1 & 2 & 3 & 4 & 5 \\\hline \text { Score, } \mathrm{y} \text { (in percentage) } & 86.2 & 85.7 & 85.4 & 85.2 & 85.0\end{array}$
Using a graphing utility, fit a logarithmic function $y = a + b \ln x$ to the data. Using the function you found, estin how long will it take for the test scores to fall below $84 \%$ . Express your answer to the nearest month.

A) 8 months
B) 12 months
C) 20 months
D) 10 months