What is the correct sequence for connecting and disconnecting the earthing (grounding) cable during loading of a flammable liquid tanker?

1. Connect the hose first, then the earth cable; disconnect in the same order
2. Connect the earth cable before any other connection is made; disconnect it only after all hoses have been disconnected
3. Earth cables are only connected after loading is fully completed
4. The sequence does not matter as long as both are connected at some point