Personally, I find the US answer more plausible. because of the existence of the two bar version. It's much more likely for people to simplify the two bar version by dropping a bar than to pointlessly complicate the symbol by adding an extra bar for no reason, so I suspect the two bar version was the original.
Personally, I find the US answer more plausible. because of the existence of the two bar version. It's much more likely for people to simplify the two bar version by dropping a bar than to pointlessly complicate the symbol by adding an extra bar for no reason, so I suspect the two bar version was the original.