As per Braun's principle, yield of Ammonia will be more in Haber's process under conditions (L=Low ; H = high, T = Temp,P = Pressure)

 The production of $N{H}_3$Haber's process is also described; $N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right), ∆H_0= –92.4$, 

It is an exothermic reversible reaction that takes place with a reduction in volume. Therefore, because the forward reaction is exothermic in nature and happens with a decrease in volume, the low temperature will favor it. High pressure will therefore encourage the production of $N{H}_3$.

Therefore, the correct answer is option B) LT ; HP.