Electric organs are found in

Which one of the following groups of animals is correctly matched with its characteristic feature without any exception?

Statement $X$: Boat-shaped body,skin covered with placoid scales.
Statement $Y$: Mouth is generally ventral,jaws are generally toothed.

Which one of the following is a cartilaginous fish?

Which fish gives birth to young ones?

Which of the following is a characteristic of cartilaginous fishes $(Chondrichthyes)$?