i. Oxygen shows -2,-1,+1,+2 oxidation states. ii. As we move from top to bottom in a group, the atomic radius increases, thus, the potential to form stable covalent bond with hydrogen goes on decreasing. Therefore, the correct order is: H2O>H2S>H2Te iii. Lesser the thermal stability of hydrides, the greater is reducing character, Therefore, the correct order is: H2S<H2Se<H2Te Hence, statements (i) and (iii) are correct.