For real gases van der Waals equation is written as

$(P+\frac{a{n}^2}{V^2})$ $(V-nb)$ $=$ $nRT$

where 'a' and 'b' are van der Waals constants.

Two sets of gases are:
(I) $O_2,$ $C{O}_2$ $,$ $H_2$ $and$ $He$        (II)$C{H}_4,$ $O_2$ $$ $and$ $H_2$ 
The gases given in set-I are in increasing order of 'b' and gases given in set-II are in decreasing order of 'a'. Select the correct order from the following:

1. $($ $I)O_2<He<H_2<C{O}_2(II)$ $H_2>O_2>C{H}_4$

2. $($ $I)H_2<He<O_2<C{O}_2(II)$ $C{H}_4>O_2>H_2$

3. $($ $I)H_2<O_2<He<C{O}_2(II)$ $O_2>C{H}_4>H_2$

4. $($ $I)He<H_2<C{O}_2<$ $$ $O_2\left(II\right)$ $C{H}_4>H_2>O_2$

Van der Waal's real gas acts as an ideal gas at which condition?

1. High temperature, Low pressure

2. Low temperature, High pressure

3. High temperature, High pressure

4. Low temperature, Low pressure