A white salt X gives an apple green flame. On strong heating it gives a brown gas and a gas that rekindles a glowing splint, leaving a white residue that dissolves in water to give a strongly alkaline clear solution. Excess dilute sulphuric acid added to a solution of 2.61 g of X gives a white precipitate insoluble in dilute HCl. Using Ba 137, N 14, S 32, O 16, the mass of this precipitate is

1. A2.61 g
2. B1.17 g
3. C4.66 g
4. D2.33 g