Answer:
selection effect
Explanation:
Selection effect: In sociology, the term "selection effect" is also referred to as "selection bias", and is determined as one of the biases that is being introduced at the time when different individuals, data, or groups are being selected for analyzing by the researcher or investigator in a way that is not capable of achieving "proper randomization" and therefore it ensures that a particular sample that has been gained via selection is not considered as "representative" of a specific population that is being intended to be comprehended or analyzed.
In the question above, the given statement signifies the "selection effect".