How can this requirement be met?

Universal containers(UC) has a customer Community that uses Facebook for authentication. UC would like to ensure that changes in the Facebook profile are reflected on the appropriate customer Community user.

How can this requirement be met?
A . Use the updateuser() method on the registration handler class.
B. Use SAML just-in-time provisioning between Facebook and Salesforce
C. Use information in the signed request that is received from Facebook.
D. Develop a schedule job that calls out to Facebook on a nightly basis.

Answer: A