Answer:
B) Go down
Step-by-step explanation:
pH is defined as -log [H⁺], that means when concentration of H⁺ increases the pH decreases and when concentration of H⁺ decreases, pH increases.
When a strong acid as HCl is added to a solution, it is dissolved, thus:
HCl → H⁺ + Cl⁻
Thus, addition of a strong acid decreases pH because concentration of H⁺ increases.
Right answer is:
B) Go down