The best upper bound for this number is

Question

For the standard transportation linear programme with m sources and n destinations and total demand, an optimal solution (lowest cost) with the smallest number of non-zero x_ij values (amounts from source i to destination j) is desired. The best upper bound for this number is                                                 

      (a) mn                                                                

      (b) 2(m + n)

      (c) m + n                                                            

      (d) m + n – 1