Answer: Single quote character ('), NONE

The FIELD_OPTIONALLY_ENCLOSED_BY parameter in Snowflake's COPY INTO command for data unloading accepts either a single character (such as a single quote ') or the value NONE. According to Snowflake documentation and the community discussion consensus, option A (single quote character) represents a valid character enclosure, and option D (NONE) indicates no enclosure should be used. Option B ('NULL') is invalid as it's a string literal, not the NULL keyword. Option C ('''NULL''') is an escaped string and not a valid parameter value. Option E ('''NONE''') is similarly an escaped string and incorrect. The community discussion with 100% agreement on AD and references to official documentation confirms these as the correct choices.

Author: LeetQuiz Editorial Team