Answer:
In the main idea or point used in an essay. It is usually made at the introductory paragraph where supporting paragraph are then used to support the statement. You know how we write topic sentence in a paragraph.. A thesis statement is almost the same but in an essay that statment if focused on throughout the whole essay.
To find the theme, you look for the main idea or topic.
Since the word these and the word jeans are plural, the answer is are.
