Which one of the following is NOT a strong acid?

Which one of the following is NOT a strong acid?

مندرجہ ذیل میں سے کون سا مضبوط تیزاب نہیں ہے؟
Explanation

Phosphoric acid is considered a weak acid.

Nitric acid, sulfuric acid, and hydrochloric acid are all strong acids, fully dissociating in water.