(2) is the only correct answer. (1) 5 grams of H2 is 2.5 mols of this gas, which would result at STP 22.4 * 2.5 Liters (according to Avogadro's law). 5 moles of O2 would result in 5 * 22.4 Liters, and (4) 5 * 10^23 molecules of CO2 (which is what I assume you meant) would be 5 mols, which would result in 5* 22.4 Liters.
generally element from d block can for ion with multiple charge and having incomplete outershell means element do not have fullfiled or half filed orbital because in these case it takes more energy to remove valence shell electron.
