A milling machine with a spindle speed of 100rpm has to cut a straight slot of 10 mm width and 2 mm depth by a cutter of 10 mm diameter between points (0,0) and (50,100) on the XY plane (dimensions in mm). Find the milling time (in seconds), if the cutter has 5 teeth, and feed fT is .15mm.
A. 1.5
B. 90
C. 7.5
D. 450