You have a Serverless SQL pool development assigned by your company. This should follow the best practices and optimized solutions. Which of the following solutions will help you increase the performance?

Answer options:

A.Use the same region for Azure Storage account and serverless SQL pool.
B.Convert CSV to Parquet.
C.Use CETAS.
D.Use azure storage throttling.

Correct Answers: A, B and C 
When Azure Storage account and serverless SQL pool are co-located, the latency of loading will be reduced. Thus, there will be an increase in total performance. In situations where these are in different regions, data has to travel more, increasing the latency. 
Parquet is columnar formats and compressed and have a smaller size than CSV. So, the time to read it will be less. 
CETAs are parallel operations that create external table metadata and export the result of the SELECT query to a set of files in your storage account. We can enhance the query performances. Options A, B and C are correct: These are the best practices followed to improve the performance of the Serverless SQL pool.
Option D is incorrect: Storage throttling detection will slow down the SQL pool, and thus the performance will be decreased.
Reference: 
To know more about Serverless SQL pool development best practices, please refer to the doc below: 

https://docs.microsoft.com/en-us/azure/synapse-analytics/sql/develop-best-practices#serverless-sql-pool-development-best-practices