Read the following statements about parasitism and select the correct option.

(i) The human liver fluke depends on two intermediate hosts to complete its life cycle.

(ii) Natural selection always leads to the evolution of totally harmless parasites.

(iii) The life cycles of endoparasites are more complex because of their extreme specialisation.

(iv) The crow lays its eggs in the nest of the koel and lets the koel incubate them.