Answer: SELECT parse_json(NULL)

The question asks which PARSE_JSON configuration returns a valid SQL NULL value. According to Snowflake documentation and community consensus, when the input to PARSE_JSON is SQL NULL, the output is also SQL NULL. Option A (SELECT parse_json(NULL)) passes a SQL NULL directly, resulting in SQL NULL output. Option B passes the string 'null', which is interpreted as a JSON null value (not SQL NULL). Option C passes an array containing null, returning a VARIANT array. Option D passes a JSON object with a null value, returning a VARIANT object. Only Option A results in a true SQL NULL value.

Author: LeetQuiz Editorial Team