Answer:
Masters and Johnson's empirical work in human sexuality differed from that of earlier researchers because they also incorporated physiological measurements (c).
Step-by-step explanation:
In contrast to earlier researchers who primarily relied on subjective observations, Masters and Johnson revolutionized the study of human sexuality by incorporating physiological measurements into their empirical work. Their approach involved the use of instruments to monitor physiological responses, such as heart rate and blood flow, during sexual activities. This marked a significant departure from previous methodologies, allowing for a more objective and scientifically rigorous understanding of human sexual response.
The inclusion of physiological measurements provided a comprehensive perspective on sexual functioning, encompassing both psychological and physiological aspects. This methodological innovation by Masters and Johnson contributed to a more nuanced and evidence-based understanding of human sexuality, laying the foundation for subsequent research in the field.
Option C is correct.