Sentence 1: Jacob noticed his dog was whining. 
 Sentence 3: He took the dog to see the vet 
 Sentence 4:  The vet made a cast to set the hurt leg 
 Sentence 5:  Within a few weeks, Jacob and his dog were playing again! 
 Option 1: Jacob investigated and found a laceration on his dog's belly. 
 Option 2: Jacob investigated and found his dog's leg hurt.