Answer:
B. Observational measurement
Explanation:
Observational measurement: The term observational measurement is also denoted as field research and is defined as one of the correlational research methods in which an experimenter or researcher tries to observe the behavior of the participants in the natural setting and make a quantitative judgment related to the behavior.
Types: Participant observation, field experiments, and structured observation.
In the question above, the given statement is an example of observational measurement.