Solve the Problem $A ( x ) = 100 \mathrm { e } ^ { - 0.01828 x }$

Multiple Choice

Solve the problem.
-Suppose the amount of a radioactive element remaining in a sample of 100 milligrams after x years can be described by $A ( x ) = 100 \mathrm { e } ^ { - 0.01828 x }$ . How much is remaining after 50 years? Round the answer to the nearest hundredth of a milligram.

A) $91.40$ milligrams
B) $249.43$ milligrams
C) $0.40$ milligrams
D) $40.09$ milligrams