Your company has large data sets that need to be streamed directly into Amazon S3. Which of the following would be the easiest way for such a requirement?

Answer options:

A.Kinesis Data Streams
B.Kinesis Data Firehose
C.AWS Redshift
D.AWS DynamoDB

Answer – B
The AWS Documentation mentions the following.
Amazon Kinesis Data Firehose is a fully managed service for delivering real-time streaming data to destinations such as Amazon Simple Storage Service (Amazon S3), Amazon Redshift, Amazon Elasticsearch Service (Amazon ES), and Splunk. 
Option A is partially valid, but since the stream of data needs to go directly into S3, Firehose can be used instead of Kinesis streams.
Option C is invalid because this is used as a petabyte warehouse system.
Option D is invalid because this is an AWS fully managed NoSQL database.
Reference:
https://docs.aws.amazon.com/firehose/latest/dev/what-is-this-service.html