For compliance with PCI DSS, what is mandatory for third-party service providers?

For compliance with PCI DSS, third-party service providers are indeed required to undergo annual security assessments. This requirement is essential to ensure that these service providers maintain a secure environment that adequately protects cardholder data. The annual security assessments help identify vulnerabilities and ensure that appropriate security measures are in place to mitigate risks associated with handling sensitive information.

Conducting these assessments allows service providers to regularly evaluate their security protocols, make necessary updates, and remain compliant with the standards set forth by PCI DSS. It's a proactive approach aimed at minimizing potential risks that could jeopardize the security of payment card transactions and the integrity of cardholder data.

While other options may represent useful practices in a business context or contribute to overall security and customer satisfaction, they do not specifically align with the requirements outlined in PCI DSS regarding third-party service providers.