As a developer, you are developing an application that will carry out the task of uploading objects to the Simple Storage service. The size of the objects varies from 300MB – 500 MB of size. Which of the following should you do to minimize the amount of time that is used to upload an item?

Answer options:

A.Use the BatchWriteItem command.
B.Use Multipart Upload.
C.Use the MultiPutItem command.
D.Use the BatchPutItem command.

Answer - B
This is mentioned in the AWS Documentation.
Multipart upload allows you to upload a single object as a set of parts. Each part is a contiguous portion of the object`s data. You can upload these object parts independently and in any order. If transmission of any part fails, you can retransmit that part without affecting other parts. After all parts of your object are uploaded, Amazon S3 assembles these parts and creates the object. In general, when your object size reaches 100 MB, you should consider using multipart uploads instead of uploading the object in a single operation.
Option A is incorrect because the 
BatchWriteItem
 operation is used for DynamoDB instead of S3.
Option C is incorrect as there is no such command present in S3.
Option D is incorrect because there is no such command in S3. The APIs of BatchGetItem and BatchWriteItem belong to the DynamoDB service.
For more information on high-resolution metrics, please visit the following URL-
https://docs.aws.amazon.com/AmazonS3/latest/dev/uploadobjusingmpu.html