Alan became Hooper’s Store proprietor in Sesame Street’s 1998 redesign.
Alan, played by Alan Muraoka, took over the fictional neighborhood store after Mr. Handford retired and sold it. Muraoka joined the cast in 1998, and Alan has remained associated with Hooper’s Store ever since. In the show’s later presentation, the store functions as both a general shop and a social meeting place for residents of Sesame Street.
The store’s ownership history is easy to muddle. Mr. Hooper was the original proprietor, and after actor Will Lee died in 1982, David became the in-universe owner. David left in 1989, when the retired firefighter Mr. Handford took over. Carlo worked there during the 1990s but was an employee, not the proprietor.
Chris later worked part-time at the store, while Alan remained its owner and central adult presence. Thus, David and Mr. Handford are valid answers for earlier eras, but the question’s 1998 date points specifically to Alan.