The website that you're referring has different option of the same question now.
So I think your answer is correct and with updated option, it should be option "D".
Regarding your second question, if you read the below paragraph from that site, especially the line that I highlighted. According to that your answer 'A' is correct.
The Sweeney Todd story also made its way into musicals and
comedies. Controversy still exists over whether Thomas Prest’s
character was based on a real person. No records of a barber
shop on Fleet Street, or a barber named Sweeney Todd have been
found, though Thomas Prest was known for getting his
inspiration from “The Old Bailey” of the London Times, a section
devoted to real-life horror stories.
I would suggest you to avoid that site and spend time elsewhere.
P.S: I'm not associated in any way with suggested site.