Answer: Scaling up

The question asks about increasing a virtual warehouse's size from X-Small to X-Large, which is a classic example of 'scaling up' (vertical scaling). Scaling up involves adding more resources (CPU, memory) to an existing node, which is exactly what happens when moving from smaller to larger warehouse sizes in Snowflake. The community discussion shows 100% consensus on option D, with multiple users confirming this is correct and referencing Snowflake documentation that supports warehouse resizing for performance improvement. 'Right sizing' (A) refers to selecting the appropriate initial size, not the act of increasing size. 'Concurrent sizing' (B) is not a standard Snowflake term. 'Scaling out' (C) refers to horizontal scaling by adding more nodes, which is different from increasing the size of a single warehouse.

Author: LeetQuiz Editorial Team