Correct Answer : Option (B) :   Requirements of removing number of major structural elements
                                                                                                                
                                                                                                                                                                        
                                                        Explanation : Easily accessible and reachable parts are primary requirement of maintainability considerations. Accessibility directly affects the effort and maintainability of an aircraft. If a design requires removal of major structural elements to access the component then, it is considered as the worst design based on maintainability.