In Van der waal's equation of state of the gas law the constant 'b' is a measure of :

Question

$\begin {array} {1 1} (a)\;Intermolecular \;collisions\; per\; unit\; volume\\(b)\;Intermolecular\; attractions\;\\(c)\;Volume\; occupied\; by\; the\; molecules\\(d)\;Intermolecular\; repulsions \end {array}$