Correct Answer - C
(A)According to VSEPR theory, as electronegativity of central atom decreases, bond angle decreases.So bond angle of `H_2O gt H_2S gt H_2Se gt H_2Te`
(B)`C_2H_2 gtC_2H_4 gt CH_4 gt NH_3`.In `NH_3` there is bp-lp repulsion so bond angle decreases to `107^@` from `109.5^@`
`{:(sp,sp^2,sp^3,sp^3),(180^@,120^@,109.5^@,107^@):}`
( C)The correct order is `{:(SF_6lt,OF_2lt,H_2Olt,NH_3),(90^@,102^@,104.5^@,107^@):}`
(D)`CIO_2 gt H_2O gtH_2S gtSF_6`
`{:(sp^2,sp^3,---,sp^3d^2),(~~117^@,104.5^@,92^@,90^@):}`