Answer:
A. True
Step-by-step explanation:
Loss to follow-up: In psychological research, the term "loss-to-follow-up" is described as a process that occurs when an experimenter or researcher lose his or her contact with the participants in a specific trial for reasons like migration or in fact the failure to maintain some contact prior to the termination or end of a research or study or of any planned endpoints.
It often leads to create bias while researching through observational method as the observation depends on the researcher itself.
The answer for the question above is True.