Which of the following is important when securely attaching a gas cylinder?

When securely attaching a gas cylinder, ensuring that it is firmly connected is crucial to preventing leaks. A gas cylinder that is not properly secured can lead to the release of gases, which may pose serious safety hazards including fire risks, health risks from inhalation, or even explosions in certain situations. A secure connection also contributes to maintaining pressure within the cylinder and ensuring proper delivery of the gas when it is needed. It is critical to follow manufacturer guidelines and safety protocols during this process to guarantee that the connection is both safe and reliable, thereby protecting both personnel and equipment.

The other choices miss the key focus on safety and proper technique in securing the gas cylinder. For instance, acting quickly may introduce carelessness, using no tools can lead to insufficient fastening, and while ensuring the cylinder points away from people is indeed a safety measure, it does not address the immediate need for a secure connection which is paramount in preventing leaks.