What is a potential consequence if not all motors in a cluster ignite at launch?

If not all motors in a cluster ignite at launch, the most significant consequence is that the rocket may not fly straight. This scenario can lead to an uneven thrust being produced, which can result in a yawing motion. When one or more motors fail to ignite, the asymmetric thrust can cause the rocket to veer off its intended trajectory, potentially leading to instability during ascent and affecting the overall performance of the rocket.

The other choices do not accurately reflect the outcomes of a failed motor ignition. For example, the rocket achieving a higher altitude does not logically follow from having uneven thrust; rather, it is likely to achieve less altitude due to potential loss of control. Additionally, while a decrease in flight duration might occur if the rocket veers off course and experiences structural failure, it is not a direct consequence of unequal motor operation. Lastly, the rocket exploding on launch is an extreme scenario that typically results from severe malfunctions or design flaws rather than simply from one or more motors failing to ignite.