Go CCIE Go!! - A Cisco Certified Internetwork Expert

Guys,
Struggling to find the correct way to emulate vtp pruning using switchport trunk allowed vlan command..
Question is from InternetExpert Lab 28 Also says to only send the minumum amount of traffic necessary across these trunk links

Eg,
Sw1 has hosts in vlan 100,28,46,5 Also has interface vlan 7 (but no interfaces in the vlan)
Sw2 has hosts in vlans 34,100 Also has interface vlan 8 and 28 (but no interfaces in the vlan)
What do you guys think is the correct solution.
Solution 1.(only allows vlan traffic to other side that both switches have hosts in. eg 100) SW1. switchport trunk allowed vlan 100
SW2 switchport trunk allowed vlan 100

Solution 2. (allows vlan traffic to other side that the OTHER side has hosts in as well as interface vlans ((28) where this traffic must traverse the trunk) SW1 switchport trunk allowed vlan 34,100,28
SW2 switchport trunk allowed vlan 100,28,46,5
Solution 3. (allows vlan traffic to other side that the OTHER side has hosts in as well as all interface vlans on the other side) SW1 switchport trunk allowed vlan 34,100,28,8
SW2 switchport trunk allowed vlan 100,28,46,5,7

Solution 4, (Their solution. Confused about the logic)
SW1. switchport trunk allowed vlan 7.28,100 SW2 switchport trunk allowed vlan 8.28.100
Or others
Any ideas about the best way?
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