A developer wants users to access AWS resources using temporary security credentials. Which AWS service should the developer use to issue these temporary credentials?

AWS Security Token Service (STS) is the correct choice because it is a web service that enables you to request temporary, limited-privilege credentials for AWS Identity and Access Management (IAM) users or for users that you authenticate (federated users). These temporary credentials are ideal for granting access to AWS resources for a defined period, enhancing security by reducing the risk associated with long-term credentials. IAM policies define permissions but don't issue credentials. IAM user groups organize users but don't provide temporary credentials. AWS IAM Identity Center (AWS Single Sign-On) manages access to multiple AWS accounts and applications but relies on STS for issuing temporary credentials for federated access.