The correct order of query optimization is:

The correct answer is B. Querying, Scanning, Parsing, Validating.

Explanation:
1. Querying: The process begins with Formulating a query to fetch data.
2. Scanning: This involves reading through the data to find relevant information based on the query conditions.
3. Parsing: In this step, the query is analyzed for its structure and components, breaking it down into a format that can be processed.
4. Validating: Finally, the system checks for any errors or inconsistencies in the query and ensures that it adheres to the set rules before execution.

This order is typically followed in query optimization to ensure efficiency and accuracy. If you have any more questions or need further assistance, feel free to ask!