What factors motivate a MT fuze?

The correct choice highlights that centrifugal force and wound springs are key factors that motivate a mechanical time (MT) fuze. When a munition is launched, it often experiences rapid rotational motion due to centrifugal force. This force is significant because it can initiate the fuzing mechanism by moving components within the fuze to the arming position.

Wound springs also play a critical role, as they provide the necessary tension or energy needed to engage or disengage certain mechanisms within the fuze. As the munition accelerates and stabilizes in flight, these springs ensure that the fuze is adequately armed and ready to function at the intended moment, typically shortly before impact or at a predetermined time.

The other options do not accurately capture the essential elements that motivate a mechanical time fuze in terms of operation and activation. For instance, gravity is a force that acts on an object in a vertical direction and might not directly influence the timing or arming mechanism of typical fuze designs. Similarly, firing pins and sliders are found in other types of fuzes but are not the primary motivating factors for a mechanical time fuze, which relies more on centrifugal force and spring mechanisms to operate effectively.