A Christmas Carol

On Christmas Eve in 19th-century London, Ebenezer Scrooge, a miserly old money-lender at a London counting house, does not share the merriment of Christmas. He declines his cheerful nephew Fred's invitation to a Christmas dinner party and dismisses two gentlemen collecting money for charity. His loyal employee Bob Cratchit offers Scrooge to have Christmas off, since there will be no business for Scrooge during the day. Scrooge agrees and leaves. In his house, Scrooge encounters the ghost of his deceased business partner Jacob Marley, who warns him to repent his wicked ways or he will condemned in the afterlife like he did, carrying heavy chains forged for his own greedy ways. He informs Scrooge that three time-travelling spirits will visit him for the next three nights.
At one o'clock, Scrooge is visited by the candle-like Ghost of Christmas Past, who takes him back in time to his early life. They visit Scrooge's boarding school and Scrooge sees his sister Fan, who died after giving birth to Fred. Scrooge later begins a successful career in business and money lending as an employee under Fezziwig, and he becomes engaged to a woman named Belle. However, the Ghost shows Scrooge how Belle left him when he chose his wealth over her. A devastated Scrooge extinguishes the spirit with its candle snuffer cap as he returns to the present.
At two o'clock, Scrooge meets the merry Ghost of Christmas Present, which shows Scrooge the joys and wonder of Christmas Day. Scrooge and the Ghost visit Bob's house, learning his family is content with their small dinner, Scrooge taking pity on Bob's ill son Tiny Tim. The Ghost abruptly ages, commenting that Tiny Tim will likely not survive until next Christmas. Before dying, the spirit warns Scrooge about the evils of "Ignorance" and "Want"; Big Ben begins tolling the hour as "Ignorance" and "Want" manifest themselves before Scrooge as two wretched children who grow into violent, insane individuals, leaving the spirit fading into dust.
The Ghost of Christmas Yet to Come arrives, appearing as a silent, cloaked shadow, and takes Scrooge into the future. A group of businessmen discuss the death of an unnamed colleague, but do not mourn him; he discovers that his possessions are stolen and sold by his maid, and a young couple who owed Scrooge money are relieved he is dead, as they have more time to pay off their debt. The spirit transports Scrooge to Bob's residence where he learns Tiny Tim had died. The Ghost escorts Scrooge to the cemetery, where the Ghost points out his own grave, revealing Scrooge to be the dead, unmourned man. Scrooge decides to change his ways just as the Ghost forces Scrooge to fall into his empty coffin sitting in a deep grave atop the fires of Hell.
Awakening in his bedroom on Christmas Day, he finds the ghosts had visited him all in one night instead of three. Gleeful at having survived the spirits, Scrooge decides to surprise Bob's family with a turkey dinner while remaining anonymous, and ventures out with the charity workers and the citizens of London to spread happiness in the city. The following day, he gives Cratchit a raise and becomes like "a second father" to Tiny Tim, who escapes death. A changed man, Scrooge now treats everyone with kindness, generosity, and compassion; he now embodies the spirit of Christmas.

Question: Who decides to surprise Bob's family?
Answer: Scrooge