Which sentence expresses a complete thought?

After they spoke to each other.
Although they said hello.
As soon as they saw each other, they said hello.
As soon as they recognized each other

Question

Which sentence expresses a complete thought? 
  
 After they spoke to each other. 
 Although they said hello. 
 As soon as they saw each other, they said hello. 
 As soon as they recognized each other

data_lg2 · Answer

Which sentences do you think are incomplete or contain missing clauses and which one do you think is complete? Any thoughts?

marc_d · Answer

Hmm,what do u think? @Faithj342275

kirby5687 · Answer

The third sentence is a complete thought. It includes a punctuation and has a comma as well.