To ensure that your research project is manageable, you must be sure that your topic is broad enough for the audience to relate to narrow enough to be presented thoroughly historical, so there will be plentiful sources on something you feel strongly about

To ensure that your research project is manageable, you must be sure that your topic is narrow enough to be presented thoroughly.

Explanation:

You should keep the topic narrow, so you keep the focus of your research and leave the topic with specific content without running away from the subject covered. When you keep a narrow topic, you can more easily perceive what information should be included in your research to keep the public interested and curious about your project.

the answer should be:

the intervention of the supernatural gives gilgamesh hope that he will defeat humbaba.