$\text { The force } F \text { (in newtons) of a hydraulic cylinder in a press is proportional to the }$

Multiple Choice

$\text { The force } F \text { (in newtons) of a hydraulic cylinder in a press is proportional to the }$ square of $\sec x$ where $x$ is the distance (in meters) that the cylinder is extended in its cycle. The domain of $F$ is $[ 0 , \pi / 3 ]$ and $F ( 0 ) = 400$ . Find the average force exerted by the press over the interval $[ 0 , \pi / 3 ]$ . Round your answer to the nearest whole number.

A) 221 newtons
B) 110 newtons
C) 540 newtons
D) 180 newtons
E) 662 newtons