Which of the following best describes the purpose of a fusible plug?

A fusible plug is a safety device specifically designed to release pressure in case of a fire or excess temperature. This component is typically made from a material that melts at a predetermined temperature. When the surrounding temperature rises due to a fire or other heat source, the fusible material melts, creating an opening that allows gases or fluids to escape. This release of pressure helps to prevent explosions or catastrophic failures that could occur if the pressure were to build up unchecked.

By understanding the function of a fusible plug, it's clear that its primary role is to manage pressure in potentially hazardous situations, making it an essential safety feature in various applications, such as in gas cylinders or storage tanks. The other options do not accurately reflect the specific function of the fusible plug, as they focus on aspects like temperature control, leak prevention, or flow management, which are not the main purposes of this safety device.