Who among the following organized party immediately after B?
1. P has to arrange a party on 18th June 2. M has a party in June on an even numbered date. 3. Only four people have a party between M and O. 6. Both Z and Y have to arrange a party on the same date. 7. Z has to party on one of the days after Y. 8. No one have to arrange a party between Z and B.