Consider the following Snowflake SQL query used to calculate the RMSE for a regression model's predictions, where 'actual_value' is the actual value and 'predicted value' is the model's prediction. However, you notice that the RMSE calculation is incorrect due to an error in the query. Identify the error in the query and provide the corrected query. The table name is 'sales_predictions'.

Which of the following options represents the corrected query that accurately calculates the RMSE?
Correct Answer: A
The original query uses 'AVG', which is perfectly valid. However, Snowflake also supports the 'MEAN' function, which is an alias for the 'AVG' function and is used for calculated descriptive statistics. The corrected query maintains the functionality and structure, only substituting AVG with MEAN. B and C options lack the square root function. Option D calculates the Mean Absolute Error (MAE), not the RMSE. Option E uses a window function unnecessarily.