Exercise 1: What Renders a Single Post With Only index.php, header.php, footer.php — Possible Solution ==================================================================== THE ANSWER: index.php ------------------------------ With no single-{type}-{slug}.php, no single-{type}.php, no single.php, and no singular.php present in the theme, WordPress falls all the way down this chapter's own documented single-post hierarchy to the final, universal fallback: index.php. WHY THIS FOLLOWS DIRECTLY FROM THIS CHAPTER'S OWN HIERARCHY TABLE ------------------------------ Per this chapter's own "Hierarchy for a Single Blog Post" table, WordPress checks, in order: single-post-{slug}.php, single-post.php, single.php, singular.php, and only then index.php. Since none of the four more specific candidates exist in this theme's folder, each check in turn fails to find a matching file, and the search continues down the list until it reaches the one file that IS guaranteed to exist - index.php, per Chapter 1's own description of it as the required, universal fallback. WHY THIS ISN'T AN ERROR OR A BROKEN STATE ------------------------------ This is exactly the intended, designed behavior of the hierarchy, not a failure condition - per this chapter, "the search always ends at index.php... exactly as Chapter 1 described." A minimal theme with only index.php, header.php, and footer.php is a genuinely valid, functioning theme; it simply uses the single most generic template for every page type rather than having dedicated templates for each one. HOW index.php COULD STILL BEHAVE DIFFERENTLY FOR DIFFERENT PAGES ------------------------------ Even relying entirely on index.php, this same chapter shows that conditional tags like is_single() could let that one file still detect it's rendering a single post specifically and adjust its own output accordingly - the file being used doesn't have to render every page type identically, even though the SAME file is chosen for all of them in this minimal theme. WHY THIS WORKS AS AN ANSWER ------------------------------ It identifies the correct file, traces the exact hierarchy chain from this chapter's own table explaining why every more specific candidate is skipped, and clarifies that this outcome is the designed fallback behavior rather than an error - directly citing the chapter's own language throughout.