Which tournament mentioned is part of the PGA's official roster?

The Senior PGA Championship is indeed part of the PGA's official roster and is one of the major championships for players aged 50 and older. Organized by the PGA of America, it features seasoned golfers who have demonstrated exceptional skill and competitiveness over their careers, making it a prestigious event within the realm of professional golf.

While the FedEx Cup is a significant part of the PGA Tour's schedule, it is not considered a standalone tournament but rather a season-long points competition culminating in a series of playoff events. The Grand Slam, on the other hand, is not an official tournament; it refers to a golfer's achievement of winning all four major championships in a single year.

Therefore, the Senior PGA Championship stands out as the only event in this selection that is a recognized part of the official PGA tournament roster.