The table shows the consecutive ionisation energies for an element X. Ionisation energy / kJ mol$^{-1}$: 1st = 950, 2nd = 1800, 3rd = 2700, 4th = 4800, 5th = 6000, 6th = 12300. What might the formula of a chloride of X be?
- A$\text{XCl}$
- B$\text{XCl}_2$
- C$\text{XCl}_3$
- D$\text{XCl}_4$