The answer is:  [D]:  
___________________________________________________________
They are often used to combine choppy sentences.
______________________________________________________________   
     Conjunctions are often used to combine choppy sentences.
____________________________________________________________
Note:  The questions asks about CONJUNCTIONS —NOT about "contractions".
____________________________________
Choice "A" is incorrect.  They are not used to combine two or more LONG sentences.  If sentences are already long, then do not need to be combined with a conjunction.
_____________________________________
Choice: "B" is incorrect.  To the contrary, the use of conjunctions actually makes sentences longer.
________________________________________
Choice "C" is incorrect.  To the contrary, the use of conjunctions should be used (appropriately, of course) in essays.  The use of "contractions" should not be used in essays or formal writing.
________________________________________
Choice "D" is correct.  They are often used to combine choppy sentences for better reading and engagement.
_______________________________________________________
        
                    
             
        
        
        
Using mobile phones has lots of advantages and disadvantages and most you will be aware of that. Earlier days, when we are out of home or office, we need to search for a public telephone booth to make a phone call, but now, just pick up your mobile phone and dial. I am trying to list the Pros and cons of using a mobile phone in this post. Advantages of using a mobile phone You are always connected, anybody who knows your mobile number can contact you. If you are travelling out of your territory...
        
             
        
        
        
Answer:
B. So warm and so light
Explanation:
A. Daffodils,
B. So yellow and bright!
C. you shine in the garden
B. - So warm and so light
So far it looks like an A/B/C, poem
So B. would be the correct answer
(as it's the only one that rhymes)
 
        
                    
             
        
        
        
I think this story is told in a witty an interesting way since it started where it should have finished with the funeral of the main character to create intrigue. Emily was somehow weird when the story said that there was hair on the pillow which meant that she slept next to him when he was dead.