Assertion (A): Plane mirror may form real image.
Reason (R): Plane mirror forms virtual image, if object is real.
Answer
 
  Plane mirrors
 
 
  can form real
 
 
  images if the
 
 
  object is virtual. 
 
 
  
 
 
  
  
   
 
    
   
  
- For all real objects , image formed by plane mirror is virtual
 
 
  
  
   
 
    
    
    
   
  
Thus,
- Assertion is true
 - Reasoning is true
 - But reasoning is not the correct explanation of assertion
 
So, the correct answer is (b)