Oral argument may be held by the Board in any case:
    
    
        
        (a) 
         When there is a novel issue not previously considered by the Board; or
     
    
        
        (b) 
         When in the interests of justice oral argument will serve to assist the Board in carrying out the intent of any of the Acts; or
     
    
        
        (c) 
         To resolve conflicting decisions by administrative law judges on a substantial question of law.