Answer:
Due to uncontrollable by the researcher.
Step-by-step explanation:
The case of children with hormonal abnormalities an example of a natural experiment because these abnormalities can't be controlled by the researcher or investigator. All those things which can't be controlled by the humans or researcher is considered as natural experiment. The main limitation of this experiment is the hormonal abnormalities, if the researcher is able to control this hormonal abnormalities then the experiment is longer be considered as natural experiment.