Which of the following statements accurately describes the purpose of a hypothesis?

A hypothesis is a specific, testable prediction about the relationship between variables in a study. It guides the research process by providing a clear focus for the investigation. The purpose of a hypothesis extends beyond merely stating the main idea or serving as a foundation; it is fundamentally about providing a basis for empirical testing.

In the context of nursing research, a hypothesis allows researchers to test an existing nursing theory by making predictions that can be verified through research methods such as experiments or observational studies. This systematic testing helps to either support or refute the theoretical concepts in nursing, advancing the body of evidence-based practice.

While the other options touch on aspects related to research, they do not encapsulate the specific function of a hypothesis as effectively. The description of a hypothesis as a descriptive statement is misleading; it is more of a predictive statement rather than a purely descriptive one. Hence, option C accurately reflects the role of a hypothesis in the research process, particularly in the context of testing nursing theories.