Which row indicates the conditions used to convert sulfur dioxide into sulfur trioxide in the Contact process?
- Apressure $250\,\text{atm}$, temperature $200\,^\circ\text{C}$, vanadium(V) oxide
- Bpressure $2\,\text{atm}$, temperature $450\,^\circ\text{C}$, vanadium(V) oxide
- Cpressure $250\,\text{atm}$, temperature $200\,^\circ\text{C}$, iron
- Dpressure $2\,\text{atm}$, temperature $450\,^\circ\text{C}$, iron