a+ib<=c+id is a meaningful only when

a) a²+c²=0

b) b²+c²=0

c) b²+d²=0

d) a²+d²=0

hi,

  we can, t compare two complex no. . there is no such concept . comparison will be possible only if both the no. are real.

means   b as well as d  is equal to zero. means

c) b²+d²=0