I had uploaded the answer on the image.(I couldn't submit the answer as it was showing an error.
Answer:
1. Topic.
2. Main idea.
3. All three? I don't understand what you were trying to say in the question. If you meant what to do to look for the main idea of a text, all of the above should be correct.
Explanation:
Did you have a typo? because half of these arent real words....