(A) All group 16 elements form oxides of the EO2 and EO3 type where E=S,Se,Te or Po. And these oxides produces acids on hydrolysis.
(B) SO2 is reducing while TeO2 is an oxidising agent. An oxidising agent is a substance that causes oxidation by accepting electrons; therefore, it gets reduced. A reducing agent is a substance that causes reduction by losing electrons; therefore, it gets oxidised.
(C) The reducing property increases from H2S to H2Te down the group. This is because the bond energy E−H(E=S,Se,Te) bond decreases down the group.
(D)
have six lone pairs