Final answer:
SAQ A is for Card-Not-Present merchants who outsource all cardholder data functions to PCI DSS compliant service providers, applicable only for e-commerce or MO/TO transactions, and not for face-to-face transactions.
Step-by-step explanation:
The type of Self-Assessment Questionnaire (SAQ) for Card-Not-Present (e-commerce or MO/TO) merchants, who outsource all cardholder data functions to PCI DSS compliant service providers, is SAQ A. SAQ A is designed for merchants that have fully outsourced all cardholder data processing activities, and do not store, process, or transmit any cardholder data on their systems or premises.
Since this SAQ is tailored for e-commerce or mail/telephone order (MO/TO) transactions, it's not applicable for face-to-face channels. It's crucial for merchants to confirm that all their third-party service providers are PCI DSS compliant to ensure the security of cardholder data is maintained.