Read the following statements and find out the incorrect statement(s).
a. Parasatic mode of life ensures free lodging and meals so parasitism has evolved in so many taxonomic groups from platns to higher vertebrates/
b. Many parasites have evolved to be host specific, i.e. they can parasitise only a single species of host.
c. The life-cycle of parasites are often complex, involving one or two intermediate host or vectors to facilitate parasitisation of its secondary host.
d. All parasites harm the host.
e. Lice on dogs and ticks on humans are familiar examples of ectoparasites.