Final answer:
In a freemium game, players can choose to watch ads for in-game rewards.
Step-by-step explanation:
In a freemium game, the best description of how advertising works is option c) The game is free to play, but players can choose to watch ads for in-game rewards.
In freemium games, players have the option to play the game for free, but there are often ads that players can choose to watch voluntarily in exchange for in-game rewards. These rewards can include in-game currency, extra lives, or power-ups. By offering these rewards, the game developer incentivizes players to engage with the ads, generating revenue for the developer while still allowing players to access and enjoy the game without paying upfront.