Final answer:
The correct answer is option a) Techniques.
Step-by-step explanation:
Psychologists use different research methods to explore theories, understand behavior, and study cognitive and biological processes. The term that refers to procedures used in these research methods is techniques. These techniques can include experiments, which are important for testing hypotheses, as well as observational studies, surveys, case studies, and in-depth interviews.
For instance, developmental psychologists use a variety of these approaches to understand changes over time in individuals, and Sigmund Freud used extensive interviews as part of his case studies to develop theories on human personality.