Solve the Problem $Q ( t ) = 4 e ^ { - 0.00938 t }$

Multiple Choice

Solve the problem.
-If the function $Q ( t ) = 4 e ^ { - 0.00938 t }$ models the quantity (in $\mathrm { kg }$ ) of an element in a storage unit after $t$ years, how long will it be before the quantity is less than $1.5 \mathrm {~kg}$ ? Round to the nearest year.

A) $105 \mathrm { yr }$
B) $31 \mathrm { yr }$
C) $45 \mathrm { yr }$
D) $4 \mathrm { yr }$