Answer:
d. parthenogenesis
Explanation:
Option a is incorrect because there are no males to couple with, hence, the reproduction cannot be a sexual one.
Option b is incorrect because fishes do not reproduce by budding.
Option c is incorrect because cloning is an artificial propagation.
Parthogenesis is a form of reproduction that occur without fertilization. The fishes must have been laying eggs which give rise to their younger ones without the need for sperm.
The correct option is d.
