the group of words a simple sentence, a compound sentence, or a run-on sentence?

Whales swim in deep water but surface for air.

A.
compound sentence

B.
run-on sentence

C.
simple sentence

Question

the group of words a simple sentence, a compound sentence, or a run-on sentence? 


Whales swim in deep water but surface for air.
  
 
 

 
 

  

  A. 
  compound sentence   
   

 
 

  

  B. 
  run-on sentence   
   

 
 

  

  C. 
  simple sentence

joclyn16 · Answer

A

awolflover1 · Answer

Hello! 

What do you think? :D

awolflover1 · Answer

@Joclyn16 Please Explain! 

A doesn't makes sense.