Answer :
I think that that the answer should be C asexual reproduction of a single-celled organism
It should be noted that when planarian is cut in half and each half usually grows back, this is C. ase-xual reproduction of a single celled organism.
What is ase-xual reproduction?
Ase-xual reproduction simply means a type of reproduction which does not involve the fusion of gametes or a change in the number of chromosomes.
From the information given, an ase-xual reproduction of a single celled organism is illustrated. In such a case, a parent separates into two or more individuals of about equal size.
It should be noted that this type of reproduction is common among single-celled organisms where the single cell divides into two daughter cells.
Learn more about ase-xual reproduction on:
https://brainly.com/question/423209