Gel electrophoresis is the movement of charged particles in a fluid or gel under the influence of an electric field. Results of this technique can be interpreted to find out if someone carries a certain gene or not.
        
             
        
        
        
D) Exercise is the answer
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Answer:
The answer is b. the theory must be changed or abandoned.
Explanation:
If a scientist finds a contradictory fact to an already existing theory, then after a scientific validation of the new found fact, the existing theory has to be changed or be replaced with a new one. 
The rest of the answer options are silly and incorrect!