The correct option is B the farm is profitable
In the last few lines of the passage, Mr. Keeble is building up the conversation and giving reasons to support the idea of him and his lending money to a 'her'- probably their daughter. He does this to persuade his wife and one of the reasons he gives is "the place is apparently coining money". In this context, 'coining money' implies that the place that is the farm is profitable. Option B is the only option that befits this context.