Which additional word in the sentence, if any, should be followed by a comma?

The solution, I believe will be found by examining the problem logically.

A.
believe

B.
found

C.
There is no error in comma usage.

D.
examining

Question

Which additional word in the sentence, if any, should be followed by a comma? 

The solution, I believe will be found by examining the problem logically.
  
 
 

 
 

  

  A. 
  believe   
   

 
 

  

  B. 
  found   
   

 
 

  

  C. 
  There is no error in comma usage.   
   

 
 

  

  D. 
  examining

geneticrockhopper247 · Answer

there should be a comma after believe because it is a little independent clause that is being used as an adjective

inowalst · Answer

@geneticrockhopper247 Please dont just give out answers. Let them think.
@1497 What do you think?