A company is running multiple AWS Lambda functions in a non-VPC environment. Most of the functions are application-specific; an operational function is involved synchronously every hour.
Recently, the Applications team deployed new functions that are triggered based on an Amazon S3 event to process multiple files that are uploaded to an S3 bucket simultaneously. The SysOps Administrator notices that the operational function occasionally fails to execute due to throttling.
What step should the Administrator take to make sure that the operational function executes?

A. Redeploy the operational function to a VPC.
B. Increase the operational function timeout.
C. Set the operational function concurrency to 1.
D. Increase the operational function memory.