The best explanation of Marley's meaning is:
B. He means that Scrooge's obsession with profit has ruined his character.
In this passage, Marley describes the chain he forged in life as a result of his own choices and actions, indicating that Scrooge has similarly created his own burdens through his greed and lack of compassion for others. The chain symbolizes the negative consequences of his obsession with wealth and profit, which has ultimately weighed down his character.