<em><u>B</u></em><em><u>. The clicking method does not work in noisy places.</u></em>
 
        
                    
             
        
        
        
If you accept either C or D as the correct revision then you have to accept both of them. Hence the best way to treat the sentence is to ignore both of them.
B is not correct either. You can over punctuate. 
That leaves A. 
Sometimes the right answer to many things is to do nothing. My dad used to say "Don't fix what isn't broke." 
A is the answer <<<<<
 
        
                    
             
        
        
        
The executioner (symbol)  He struggled as a man condemned to death struggles in the hands of the executioner, knowing that he cannot save himself. (Excerpt) The executioner symbolizes death. Ivan Ilyich realizes that he cannot escape death. (significance)
the black hole (symbol) He felt that his agony was due to his being thrust into that black hole and still more to his not being able to get right into it.(excerpt) The black hole symbolizes Ivan Ilyich’s refusal to accept death. It also symbolizes his denial that his life has lacked meaning or purpose. This denial prolongs and worsens his misery. (significance)
the light (symbol) Suddenly some force struck him in the chest and side, making it still harder to breathe, and he fell through the hole and there at the bottom was a light…  At that very moment Ivan Ilyich fell through and caught sight of the light, and it was revealed to him that though his life had not been what it should have been, this could still be rectified…   In place of death there was light.(excerpt) The light symbolizes Ivan Ilyich’s moving from the darkness and ignorance in his life into the final stage of understanding and acceptance of his condition. This acceptance helps him conquer his fear of death.
(significance)
 
        
                    
             
        
        
        
Answer:
The correct answer is: Research bias
Explanation:
Experimental bias, also known as research bias, is the phenomenon in which the <u>researcher, that is conducting the experiment or the research, influences or effects the results or outcomes of the research to give the desired or expected outcome.</u>   
A bias may arise when the researcher selects the test subjects that are more likely to generate the expected result or when the researcher influences the test subjects to give the expected result.
<u>This is influenced by the inability of a human being to remain unbiased and neutral.</u>
<u>Therefore, the given example is the demonstration of a </u><u>research bias.</u>
 
        
             
        
        
        
<span>"She said that she would come" is in formal speech.</span>