Which AWS service or feature should the company use to meet these requirement?

Explanations:

AWS DataSync is primarily used for transferring files between on-premises storage and AWS, not for streaming data from multiple sources to Amazon S3.

Amazon Kinesis Data Firehose is a fully managed service that reliably captures, transforms, and loads streaming data into data lakes, data stores, and analytics services, such as Amazon S3.

S3 Select is used to retrieve specific data from objects in S3 using SQL-like queries; it is not a data transfer or streaming service.

AWS Transfer Family enables secure transfer of files over protocols like SFTP and FTPS to Amazon S3, but it is not designed for streaming data from multiple sources.