Final answer:
Scientists find out if their hypotheses are supported by their data by analyzing the data.
Step-by-step explanation:
The stage of scientific inquiry where scientists find out if their hypotheses are supported by their data is C) analyzing data. After scientists have conducted experiments and collected data, they analyze the data to draw conclusions and determine if their hypothesis is supported or not. Analyzing data often involves using statistical, mathematical, and/or graphical methods to interpret the results.