The Introduction exists to explain the research project and to justify why this research has been done. The introduction will discuss:
The "Introduction" is where you are most likely to find the research question.
The research question may not be clearly labeled in the Introduction. Often, the author(s) may rephrase their question as a research statement or a hypothesis. Some research may have more than one research question or a research question with multiple parts.
These are some common word choices authors make when they are describing their research question as a research statement or hypothesis.
You might also look for common question words (who, what, when, where, why, how) in a statement to see if it might be a rephrased research question.