What might occur if a gas pump is not approved by the relevant authorities?

Choosing the option stating it could lead to safety hazards is correct because gas pumps that have not been approved by the relevant authorities may not meet established safety and operational standards. These standards are set to ensure that the equipment is safe for use, minimizes the risk of accidents such as leaks or fires, and protects the health of consumers and the environment. An unapproved gas pump might have faulty mechanisms, improper installation, or even use materials that are not up to code, leading to hazardous situations. These risks underscore the importance of operating equipment that has been vetted and sanctioned by regulatory bodies, which focus on public safety and compliance with industry standards.

The other options do not effectively address the implications of using non-approved equipment. For example, efficiency is not necessarily a factor of approval status; an obsolete pump may still operate efficiently until it fails or becomes outdated by newer technologies. Maintenance markings are typically reserved for equipment that is operational but requiring servicing, which does not correlate with the approval status.