Which of the following solutions would have same pH?

$100 \mathrm{mL}$of $0.2\mathrm{M} \mathrm{HCl}+100 \mathrm{mL}$of$0.4{\mathrm{MNH}}_3$

$50 \mathrm{mL}$of $0.1\mathrm{M} \mathrm{HCl}+50 \mathrm{mL}$of $0.2 {\mathrm{MNH}}_3$

$100\mathrm{mL}$of $0.3\mathrm{M} \mathrm{HCl}+100\mathrm{mL}$ of $0.6{\mathrm{MNH}}_3$

All will have same pH