Which sentence should appear first in an effective summary of Part 2 of "The Adventure of the Blue Carbuncle"?
a. The owner of the hat, Henry Baker, pays a visit to Holmes after spotting the advertisement in the newspaper.
b. Holmes and Watson learn from the innkeeper the goose was purchased from a market in Covent Garden.
c. Holmes and Watson visit the innkeeper who sold the goose to Baker.
d. Holmes and Watson set out to find the salesperson at Covent Garden.