Which of the following orders are correct as per the properties mentioned against each?

Column I Column II
(a) As2O3 < SiO2 < P2O3 < SO2            (i) Acid strength.
(b) AsH3 < PH3 < NH3           (ii) Enthalpy of vaporisation.
(c) S < O < Cl < F          (iii) More negative electron gain enthalpy.
(d) H2O > H2S > H2Se > H2Te              (iv) Thermal stability.

1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)