For the reaction ${\mathrm{Cl}}_2\left(\mathrm{g}\right)\rightleftharpoons 2\mathrm{Cl}\left(\mathrm{g}\right)$. the formation of $\mathrm{Cl}\left(\mathrm{g}\right)$ is favoured at high temperature and low pressure

The formation of chlorine is an exothermic reaction. Hence, forward reaction is favored at low temperature as heat is evolved during forward reaction which nullifies the effect of low temperature.
The reaction proceeds with decrease in the number of moles of gaseous species. Hence, forward reaction is favored with increase of pressure.

Hence option A is correct