The Percent $P$ Of the Drug Triazolam (A Drug for Treating Insomnia) Remaining

Multiple Choice

The percent $P$ of the drug triazolam (a drug for treating insomnia) remaining in a person's bloodstream after t hours is given by $P = e ^ { - 0.3 t }$ . What percent will remain in the bloodstream after 9 hours?

A) $\quad 0.9 \%$
B) $\quad 15.4 \%$
C) $\quad 6.7 \%$
D) $\quad 5.4 \%$
E) $\quad 0.1 \%$