Starting with the original Donkey Kong in 1981 (Mario's first appearance), the Mario franchise has sold over 689 million copies, with 'Super Mario' titles making up 362 million of that. Other major selling games that are considered part of the Mario franchise include the Mario Kart series (over 150 million copies), Mario Party and Mario Sports.
It wasn't listed in the possible answers, but Tetris is the second best-selling game franchise with roughly 500 million sales courtesy of its popularity as a download among mobile phone owners
Activision blockbuster Call of Duty has sold an impressive 400 million copies over the years, taking the third spot, thanks to its yearly release cycle with excellent sales figures year in and year out. Call of Duty is also the best-selling first-person shooter game and top game franchise created in the United States.
In fourth place with about half as many unit sales as Mario, some 365 million copies of Pokémon have been sold since the 1996 Japanese release of the original Pokémon RPG for Game Boy.
Finally, Grand Theft Auto and FIFA are roughly tied at 320 million although the latter is also on a yearly release cycle, GTA is a huge blockbuster with only a handful of games released in the franchise's history. Madden NFL has been around since 1988 and is surprisingly far down the list behind The Sims, Need for Speed, Final Fantasy as well as Minecraft and Sonic.