A Pharmaceutical Company Claims That the Concentration of a Drug $C ( t ) = \frac { 900 t } { 6 t ^ { 2 } + 30 }$

Multiple Choice

A pharmaceutical company claims that the concentration of a drug in a patient's bloodstream will be at least 25 % for 8 hours. Suppose that clinical tests show that the concentration of the drug (as a percent) thours after injection is given by $C ( t ) = \frac { 900 t } { 6 t ^ { 2 } + 30 }$
During what time period is the concentration at least 25 % ?

A) $1 \text { hours } \leq t \leq 5 \text { hours }$
B) $2 \text { hours } \leq t \leq 10 \text { hours }$
C) $1 \text { hours } \leq t \leq 9 \text { hours }$
D) $0 \text { hours } \leq t \leq 8 \text { hours }$