100 mL of 0.l M HCI solution is mixed with 50 mL of $0.05 \mathrm{M} \mathrm{NaOH}$. The resultant solution will have pH

100 mL of0.l M HCI solution is mixed with 50 mL of 0.05 M NaOH. The resultant solution will have pH 2.12.

To create sodium chloride solution and water, sodium hydroxide solution combines with hydrochloric acid solution. The resulting sodium chloride solution has a pH below 7, which is acidic by definition. Hence The resulting solution's pH will be 2.12.

Hence the option C is correct.