Read the passage and answer the question. 'In many villages of Kwara State, the nearest bank is a two-hour journey away, and for years farmers kept their savings in clay pots or with the village head. The arrival of mobile money agents has changed that. A farmer can now sell yams at the weekly market, receive payment on his phone, and pay his children's school fees the same afternoon without touching a single naira note. The agents themselves are usually young people who had no work before; the commission they earn on each transaction has become a livelihood. Yet the system has its weaknesses. Network failures can lock a family out of its own money for days, and a few agents have vanished with customers' deposits.' In the sentence 'The arrival of mobile money agents has changed that', the word 'that' refers to