Which sentence combines these two sentences through the use of an appositive?

Diamond is our dog. Diamond always jumps up on us when she's excited.


Diamond is our dog, and Diamond always jumps up on us when she's excited.


Diamond always jumps up on us when she's excited, and Diamond is our dog.


Diamond our dog always jumps up on us when she's excited.


Diamond, our dog, always jumps up on us when she's excited.