Its life in hours, if the load is increased to 20 kN, keeping all other conditions same, is

Question

The life of a ball bearing at a load of 10 kN is 8000 hours. Its life in hours, if the load is increased to 20 kN, keeping all other conditions same, is                    

      (a) 4000                                                              (b) 2000

      (c) 1000                                                              (d) 500