Shield block vs. multiple damage types on one attack

[breithauptclan]

We encountered an odd case when fighting the slime monster in the first room. I used shield block against its slam attack.

The slam attack does both bludgeoning damage and acid damage. I was using a light steel shield, so hardness 5. When we rolled up damage, it ended up doing 4 bludgeoning damage and 3 acid. So there are several scenarios that we came up with.

• Shield takes 4 bludgeoning damage and acid damage does not get dealt.
  
• Shield takes 4 bludgeoning damage, 1 acid damage, gets a dent and character takes 2 acid damage.
  
• Shield takes 3 bludgeoning damage, 2 acid damage, gets a dent and character takes 1 bludgeoning damage and 1 acid damage.
  
• Shield takes 4 bludgeoning damage. 3 acid damage is also applied to the shield, causing it to take a dent.
  

We finally settled on the last option. What do you guys think?

[Nuwar]

Hmm,
After thinking about it I think I agree with you. if you had resistance to bludgeoning 4 and resistance to acid 4 you would not take any damage from that attack.

Seems like a good thing to clarify.