Answer - B.
The AWS Documentation mentions the following.
An IAM role is similar to a user, in that it is an AWS identity with permission policies that determine what the identity can and cannot do in AWS.
However, instead of being uniquely associated with one person, a role is intended to be assumable by anyone who needs it.
Also, a role does not have standard long-term credentials (password or access keys) associated with it.
Instead, if a user assumes a role, temporary security credentials are created dynamically and provided to the user.