From table:

- segment AB - Ground distance: 2 000 NM.   headwind component: 50 kt = 2240 NAM

- segment BC - Ground distance: 1 000 NM.   headwind component: 30 kt = 1067 NAM

- segment CD - Ground distance:    500 NM.  tailwind component: 70 kt   =   436 NAM

- segment DE - Ground distance: 1 000 NM.   headwind component: 20 kt = 1048 NAM

                                                                                                                                                4791 NAM

                                                                                                                        (correct answer 4800 NAM)