The Temperature at a State Park for One Day in June

Multiple Choice

The temperature at a state park for one day in June can be approximated by the function $T ( x ) = 0.284 x ^ { 2 } - 5.11 x + 82 \quad 0 \leq x \leq 18$ where T is degrees Fahrenheit and x is the number of hours after 5 PM on Friday. At what time is the temperature lowest? Round to the nearest hour.

A) 2 AM
B) 9 AM
C) 11 PM
D) 5 PM