[Grammar] 3 months' notice

[Will17]

Hello!

Which is right please,

My boss wants to dismiss me. He must give me:

- a 3 month prior notice

-a 3 months' prior notice

-3 months' prior notice

-3 months prior notice

Thank you
W

 

[kimhaze]

I think it should be
3-month prior notice

 

[5jj]

My boss wants to dismiss me. He must give me:

- [STRIKE]a 3 month prior notice[/STRIKE] [STRIKE]-a 3 months' prior notice[/STRIKE] [STRIKE]-3 months prior notice[/STRIKE]

-3 months' prior notice :tick:

5