The Boston Celtics have exercised options on Jayson Tatum and Robert Williams, according to multiple reports. Shams Charania of The Athletic and Stadium broke the news on Tatum, while Keith Smith of Yahoo Sports relayed the Williams tidbit: The Boston Celtics have exercised forward Jayson Tatum's $9.9M fourth-year team option, league sources tell @TheAthleticNBA @Stadium. […]