Answer: FLATTEN

The FLATTEN function is specifically designed to convert semi-structured data (like JSON, arrays, or objects) into a relational format by breaking down nested structures into rows and columns. This makes it the correct choice for transforming semi-structured data into a tabular representation. The community discussion shows 100% consensus on option C, with multiple comments and upvotes confirming FLATTEN as the correct answer. Other options are incorrect: CHECK_JSON validates JSON syntax but doesn't convert data, TO_JSON converts data to JSON format (the opposite of what's needed), and PARSE_JSON interprets a string as JSON but doesn't flatten it into relational format.

Author: LeetQuiz Editorial Team