Another question that requires no language in programming, the question is
Your father has been known to use the titles of his favorite books as passwords. While you don't remember any of the names of the books, your father keeps a poster for one of them on his wall. Can you figure out the name of the book and unlock the CD?Copy the image URL (https://picoctf.com/problem-static/misc/robo-photo/robophoto.jpg), and go to Google Images. Click on the camera icon:
Paste the URL into the box, then press 'Search by Image'.
Going through the page, there doesn't appear to be any book title names anywhere, so just click 'Visually similar images', since it looks as though the image is just a section of an entire book cover and there should be a match to that image somewhere.
Clicking on the first image that shows up, the entire cover of the book is shown (along with the title and author).
The flag, also known as the title of the book, is The Positronic Man.