A preliminary explanation of a phenomenon; Forming is the first step of the scientific method.

• A. Falsifiable
• B. Data
• C. Scientific method
• D. Hypothesis

Answer: (D)

A hypothesis is a tentative explanation for a phenomenon that can be tested through observation and experiment. This fits the idea of a “preliminary explanation” because it is a specific statement about how variables relate that you can evaluate with data. Forming a hypothesis is often one of the first concrete steps in the scientific process after noticing a phenomenon and asking questions, because it provides a clear prediction to test.

Falsifiable describes the property that a good hypothesis should have—being testable and disprovable—but it’s not the explanation itself. Data are the information you gather to test the hypothesis, not the explanatory statement. The scientific method refers to the overall process, including observation, hypothesis formation, testing, and analysis, not the single initial explanation. Hypothesis directly captures the idea of a preliminary explanation you intend to investigate, which is why it’s the best answer.