Who can authorize GPC purchases?

The correct choice centers on the fact that only trained cardholders have the authority to make purchases using the Governmentwide Commercial Purchase Card (GPC). This is crucial because GPC transactions involve the use of government funds, and to ensure accountability and compliance with regulations, only those who have received specific training and are officially designated as cardholders can execute these transactions.

Being a trained cardholder means they understand not just how to use the card, but also the legal and ethical responsibilities that come with it, including the proper justification for purchases and adherence to established limits and guidelines.

The other answers do not reflect the specific training and accountability requirements associated with purchasing using the GPC, thus underscoring the importance of having well-defined roles and responsibilities in government procurement processes.