Under the Law of the PRC on the People's Bank of China and pricing rules, what is the driver's statutory obligation regarding RMB cash payments from passengers?

1. Drivers are legally permitted to refuse all RMB cash and insist on digital mobile payments only
2. RMB cash is legal tender in China; drivers must accept RMB cash payments and are legally obligated to prepare adequate small change and coins
3. Drivers can refuse cash if the banknote is larger than 10 RMB
4. Drivers may charge an extra 20% processing fee for accepting cash banknotes