Final answer:
Psychologists use the scientific method, which involves systematic observation and experimentation (C) to investigate phenomena. This empirical approach is based on objective evidence, rather than on guessing, superstition, or personal opinions.
Step-by-step explanation:
Psychologists, like all scientists, utilize the scientific method to conduct research and explore various phenomena. This method involves systematic procedures which include making observations, formulating hypotheses, and then designing and conducting experiments to test these hypotheses. Importantly, they rely on evidence that is empirical and can be consistently observed, rather than using less scientific approaches such as guessing, intuition, or personal beliefs.
The answer to the student's question is that psychologists employ the scientific method to investigate phenomena because it involves Systematic observation and experimentation (C). This method is central to gathering and analyzing data in psychology, allowing for greater precision and repeatability in research.