DellEMC Elastic Cloud Storage ECS

I have a Question For DellEMC Elastic Cloud Storage ECS

What is the difference between S3 authentication signature version 2 and S3 authentication
signature version
4?
Questions & Answers PDF Page 3
A. Version 2 uses a shared secret and access key ID
Version 4 uses the date/region algorithm
B. Version 2 uses HMAC algorithm
Version 4 uses the credentials scope algorithm
C. Version 2 uses a namespace based signature
Version 4 uses HMAC algorithm
D. Version 2 uses the secret key to sign the request
Version 4 uses a signing key

Can Any One please tell its right answer. Question Source: https://www.certsengine.com/