whoever has not registered

[azz]

Can one say
a. Whoever has not registered, go to line B.
b. Those of you who have not registered, go to line B.
c. Whichever of you has not registered, go to line B.
?
The sentences are being addressed to 'those who have not registered'. They are orders. 'Go to line B' is the order given to those who have not registered.

They are a bit like
d. John, go to line B.
or
e. John, be quiet.

Many thanks.

[Erik_Kowal]

As far as I'm concerned, you could happily use any of a, b, or c. The caveat is that when speaking (as opposed to writing formally), there is a strong tendency to contract has not to hasn't and have not to haven't.

[tony h]

I am with Erik on this one but an additional caveat.

The sentences are a bit wordy for some scenarios. If they were signs in an arrivals hall they would need to be more pithy although there are cultural considerations.

[Erik_Kowal]

The sentences are a bit wordy for some scenarios. If they were signs in an arrivals hall they would need to be more pithy although there are cultural considerations.

For instance:

If you haven't registered: --> Line B

[Phil White]

For instance:

If you haven't registered: --> Line B

Or simply "Go to line B" (with the fact that you will be sent back to Line A if you have already registered being implicit).

[Bobinwales]

And don't forget that in the UK the word is not 'line', it is 'queue'.