The bank that Alekos works for wants to allow customers to use a new add-on application from a third-party partner they are working with. Since not every customer will want or need an account, Alekos has suggested that the bank use a SAML-based workflow that creates an account when a user downloads the app and tries to log in. What type of provisioning system has he suggested?

A JIT, or just-in-time, provisioning mechanism creates accounts when they are needed rather than creating them in advance. This is an effective method to limit the number of accounts being maintained and can be useful if the number of accounts are part of a licensing agreement that may drive costs higher if users who don't need accounts or are not using them have them. OAuth, OpenID, and Kerberos are not mentioned in the question.