Respuesta :
longitudinal data gathering is considered the least effective.
What is data gathering ?
Data collection is the procedure of collecting, measuring and analyzing accurate insights for research using standard validated techniques.
What is data gathering in research?
Data collection is the process of gathering and measuring information on variables of interest, in an established systematic fashion that enables one to answer stated research questions, observation, test hypotheses, and evaluate outcomes.
Hence, D is correct option
To learn more about longitudinal data gathering, here
https://brainly.com/question/14598772?referrer=searchResults
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