An Advantage to American Depositary Receipts (ADRs) Over Global Registered

An advantage to American Depositary Receipts (ADRs) over Global Registered Shares (GRSs) is

A) ADRs are able to be traded on equity exchanges around the world in a variety of currencies.
B) ADRs can theoretically be "traded with the sun" following markets as they open and close around the world.
C) ADRs can be traded electronically and lack any type of specialized forms like those used with GRSs.
D) None of the above, these are all advantages to trading GRSs.