A is correct according to official practice exam

A. Use a Batch Job scope to bulk insert records into the database Reliability: If you want reliability while processing the records, i.e should the processing survive a runtime crash or other unhappy scenarios, and when restarted process all the remaining records, if yes then go for batch as it uses persistent queues. Memory footprint: Since question said that there are millions of records to process, parallel for each will aggregate all the processed records at the end and can possibly cause Out Of Memory. Batch job instead provides a BatchResult in the on complete phase where you can get the count of failures and success. For huge file processing if order is not a concern definitely go ahead with Batch Job

A is correct answer. Bulk insert in database is more efficient than multiple database insert.

Should be A.

Correct Answer: A. Use a Batch Job scope to bulk insert records into the database