The correct option is C Scientific studies of human relations appear to investigate the obvious
The author mentions in the last paragraph that "It has also been proposed that just because we know so much about people intuitively, there has been less incentive for studying them scientifically; why should one develop a theory, carry out systematic observations, or make predictions about the obvious”. Therefore, the meaning conveyed by answer option (c) very well captures the essence of this text by saying that scientific studies of human relations appear to investigate the obvious. Hence, option (c) is the correct answer.