Which is not true in case of an ideal gas ?

Question

$\begin{array}{1 1} \text{(a) It cannot be convered into a liquid} \\ \text{(b) There is no interaction between molecules} \\ \text{(c) All molecules of the gas move with same speed} \\ \text{(d) At a given temperature , PV is proportional to the amount of the gas}\end{array}$