How long do the motors of a ballistic missile burn compared to its flight time?

The motors of a ballistic missile burn for a short period of time compared to the overall flight time because these missiles typically operate in two phases: the powered flight phase and the free-fall phase. During the powered flight phase, which is when the missile's motor is ignited, it generates thrust to propel the missile upward and into its trajectory. This phase usually lasts only a few minutes.

Once the fuel is consumed, the missile then follows a ballistic trajectory, where it is essentially in free-fall. During this second phase, the missile's engines are no longer operating, and it is coasting towards its target under the influence of gravity and aerodynamic drag. The relatively short duration of engine burn, coupled with the longer free-fall time, makes the selected answer correct. The other options suggest continuous or prolonged motor operation, which isn't accurate for ballistic missile flight profiles.