According to Boyle's law, $P \propto \frac{1}{V} \Rightarrow P = \frac{k}{V} \Rightarrow PV = k$, where $k$ is proportionality constant and equal to $nRT$. Graph between $P$ vs. $V$ should be rectangular hyperbola and product of $PV$ increases with increase in temperature. Thus, option (4) is correct.