How can the erex and rex commands be used in conjunction to extract fields?

The regex generated by the erex command can be edited and used with the rex command in a subsequent search.

The regex generated by the rex command can be edited and used with the erex command in a subsequent search.

The regex generated by the erex command can be edited and used with the erex command in a subsequent search.

The erex and rex commands cannot be used in conjunction under any circumstances.