Which is the incorrect statement?

In Fasciola, excretion is done by Renette cells.

The correct answer is Option (2) -In Fasciola, excretion is done by Renette cells.

Ctenophores, commonly known as sea walnuts or comb jellies are exclusively marine, radially symmetrical, diploblastic organisms with tissue level of organisation. The body bears eight external rows of ciliated comb plates, which help in locomotion.

Phylum Platyhelminthes  have dorso-ventrally flattened body, hence are called flatworms . These are mostly endoparasites found in animals including human beings. Flatworms are bilaterally symmetrical, triploblastic and acoelomate animals with organ level of organisation. Hooks and suckers are present in the parasitic forms. Some of them absorb nutrients from the host directly through their body surface. Specialised cells called flame cells help in osmoregulation and excretion.

Earthworms are bisexual, i.e., male and female reproductive organs are present in same organism. Bisexuality favours self fertilization but earthworms are cross fertilizing organisms. This is because the male reproductive organs mature earlier than the female parts, i.e., they are protandrous, which in turn makes them cross fertilizing organisms. 

Phylum Arthropoda is the largest phylum of Animalia which includes insects. Over two-thirds of all named species on earth are arthropods . They have organ-system level of organisation. They are bilaterally symmetrical, triploblastic, segmented and coelomate animals. The body of arthropods is covered by chitinous exoskeleton.  Respiratory organs are gills, book gills, book lungs or tracheal system. Circulatory system is of open type. Sensory organs like antennae, eyes (compound and simple), statocysts or balancing organs are present. Excretion takes place through malpighian tubules. They are mostly dioecious.