Approximate the Number Using a Calculator $\mathrm { D } ( \mathrm { h } ) = 8 \mathrm { e } ^ { - 0.4 \mathrm {~h} }$

Multiple Choice

Approximate the number using a calculator. Round your answer to three decimal places.
-The function $\mathrm { D } ( \mathrm { h } ) = 8 \mathrm { e } ^ { - 0.4 \mathrm {~h} }$ can be used to determine the milligrams $\mathrm { D }$ of a certain drug in a patient's bloodstream h hours after the drug has been given. How many milligrams (to two decimals) will be present after 7 hours?

A) $0.49 \mathrm { mg }$
B) $131.56 \mathrm { mg }$
C) $5.81 \mathrm { mg }$
D) $0.29 \mathrm { mg }$