Who's 1933 speech was referred to?

Choices:
A. Hitler's
B. the customer's
C. not enough information
D. the manager's
Hitler's
TL:DR: I un-professionally get mad at a customer and verbally slam the door on her way out.
I was working a shift at a chain cafe one afternoon in England, it was during the lunch rush, so we had a back up of customers lined up to the exit.
See the problem with the chain is that all of our customers mostly range from midlife crisis to half-a-foot in the grave, so once a customer lines up, they don’t leave and they extend the queue. Plus this is a chain cafe so I've got a manager who's constantly on my back to speed up because someone is on her back to drive numbers up: this results in the line putting stress on my air-hostess smile, but they don't call it work for nothing.
Now I'm not the only one stressed, a customer lines up during lunch, they're hungry and wish that Euclidean laws would suspend themselves so that they did not have to deal with the fact that I can't deal with a customer at the speed of light. Well one eldritch horror declares that my coffee took too long and does her rendition of the 1933 Hitler speech to the rest of the customers with an addendum that she will take her business elsewhere.
Now my chain are pretty big in England, so if a customer wants to slap me around with a ‘customer is always right’ the script dictates that I do everything in my power to make sure they come back, and Cthulu knows this, well: I'm stressed, I don't like her face and she's given me an opportunity for me to give her the polite ‘fuck off'.
All I say is ‘Good’ and move on to the next customer.
Hitler-lite phones my corporation to voice a complaint, so a suit comes out and asks the team who did it, I fess up so I can save the time and not have a reason to hate one of my co-workers. I get a lecture and a warning, the end.