Need Help Understanding This Appian ACD101 Question

I am currently preparing for the Appian ACD101 exam and came across a question that I am not completely sure about.
Questions: How do you refer to the metadata of a process model object within the process model expressions? For example: the creator, name, or description.

A- Process Properties, referred to in process model expressions using the pp! domain.
B- Process Variables, referred to in process model expressions using the pv! domain.
C- Process Model Properties, referred to in process model expressions using the pm! domain.

Which option is correct, and how would you explain the reasoning behind it? I would appreciate any insights from those who have studied this topic or have recently taken the ADC101 exam.