The painkiller paracetamol is made from 4-aminophenol. Chromatography is carried out on an impure paracetamol sample. The outcome is shown. The diagram is not to scale. The paracetamol sample contains only 4-aminophenol as the impurity. What is the $R_f$ value of 4-aminophenol?
- A0.49
- B0.65
- C0.74
- D1.35