The following safety precautions must be taken to put gas back into service:

A) Checking for leaks, notifying authorities, venting gas, and repairing the leak
B) Repairing the leak, checking for leaks, notifying authorities, and venting gas
C) Venting gas, checking for leaks, repairing the leak, and notifying authorities
D) Notifying authorities, venting gas, checking for leaks, and repairing the leak

The correct sequence of safety precautions to put gas back into service includes notifying authorities, venting gas, checking for leaks, and repairing the leak, in that order. This ensures safety and compliance with regulations.

Explanation:

The correct order of safety precautions to put gas back into service after a leak or maintenance is vital for ensuring safety and compliance with regulations. The sequence involves:

Notifying authorities: Informing relevant authorities ensures that all necessary safety protocols are being followed and that you have official support in case of emergencies.
Venting gas: Safely releasing any accumulated gas to prevent buildup and reduce the risk of explosion or health hazards.
Checking for leaks: After venting, inspecting the system thoroughly to identify any leaks ensures that all issues are addressed before the gas is fully reinstated.
Repairing the leak: Finally, any detected leaks must be repaired to secure the system against future problems. It is crucial that this step is done thoroughly to ensure the safety of the system.

Therefore, the correct sequence is D) Notifying authorities, venting gas, checking for leaks, and repairing the leak. This process ensures that the system is safe to use and complies with safety standards.