Gases deviate from ideal gas behavior because the molecules $...$

In the van der Waals equation for gases,what does the constant $b$ represent?

Which among the following statements is/are incorrect regarding real gases?
$(i)$ Their compressibility factor is never equal to unity $(Z \neq 1)$.
$(ii)$ The deviations from ideal behavior are less at low pressures and high temperatures.
$(iii)$ Intermolecular forces among gas molecules are equal to zero.
$(iv)$ They obey Van der Waals equation,$PV = nRT$.

Which statement is correct regarding the equation $Z = PV/RT$?

Gases deviate from ideal behaviour at high pressures because the gas molecules

At Boyle's temperature,the compressibility factor $Z$ for a real gas is: