The Splügen Pass is mentioned in a short story featuring what fictional detective?

A Hercule Poirot
B Miss Marple
C Sherlock Holmes

The prolific Sir Arthur Conan Doyle wrote 56 short stories about Sherlock Holmes, and ‘The Adventure of the Illustrious Client’ features a villainous Austrian baron who was acquitted of his wife’s suspicious death at the Splügen Pass.

The correct answer is Sherlock Holmes.