While cranking out a quadrantal davit，slippage of the quadrant due to excessive wear or failure of the teeth in the quadrant will cause the（）.

A. Davit arm to pivot on the traveling nut and the head to fall outboard
B. Traveling nut to lock up in place on the worm gear
C. Limit switch to engage and hold the traveling nut in position
D. Winch brake to lock in position and prevent lowering the boat