Solve
-The Function $\mathrm { A } = \mathrm { A } _ { 0 } \mathrm { e } ^ { - 0.0077 \mathrm { x } }$

Multiple Choice

Solve.
-The function $\mathrm { A } = \mathrm { A } _ { 0 } \mathrm { e } ^ { - 0.0077 \mathrm { x } }$ models the amount in pounds of a particular radioactive material stored in a concrete vault, where $x$ is the number of years since the material was put into the vault. If 300 pounds of the material are initially put into the vault, how many pounds will be left after 30 years?

A) 238 pounds
B) 38 pounds
C) 50 pounds
D) 450 pounds