What is the main purpose of drilling a vent hole in the body tube?

The primary purpose of drilling a vent hole in the body tube of a rocket is to prevent vacuum formation, which can disrupt the ejection of the nose cone. When a rocket ascends, the pressure inside the body tube changes rapidly, especially at the time of deployment of recovery systems. If a vacuum were to form within the tube, it could create a situation where the nose cone is unable to be ejected smoothly or at all, risking a failure in the recovery system.

A vent hole allows air to equalize pressure, ensuring that the nose cone can separate from the body when the recovery system is activated. This is crucial for successful recovery and safe landing. The other options do not reflect the primary function of the vent hole. While they might touch upon other aspects of rocket design and performance, the key role of the vent hole is to allow for pressure equalization to facilitate the effective deployment of the recovery mechanisms.