An essay prompt is defined as a pedagogical tool used by teachers to guide students in an assignment. What makes writing essay prompts particularly difficult now is that the main challenge for teachers is trying to design prompts requiring students to read books for themselves and think for themselves rather than using student help sites as shortcuts to avoid these tasks.
One possible quotation you could use in your prompt is:
Angela stepped tentatively behind the secretary, not knowing whether to ignore her disability or take her arm. At least her crippled partner could not be the murderer, but it was embarrassing being paired with such a...
This could provide the basis for asking students to write an essay about the role of disability in The Westing Game. The point of such a prompt is that it leads to students to focus on a thematic concern rather than simply summarizing the plot of the novel. Students could choose to write either about the effects of disabilities in the lives of two or more characters or about the attitudes of other characters towards the characters with disabilities.
The more the prompt emphasizes analysis as opposed to summary, the easier it is while grading to identify the difference between a random pastiche of Google results and the results of students actually doing the assignment for themselves.