A small amount of HCl(aq) is added to a buffering system made by mixing similar molar amounts of H₂CO₃(aq) and NaHCO₃(aq). Which one of the following statements is true?

Question 19 options:

	The pH will increase slightly as H2CO3(aq) reacts with Cl-(aq)
	The pH will decrease slightly as HCO3-(aq) reacts with OH-(aq)
	The pH will decrease only slightly because HCl(aq) is a weak acid
	the pH will decrease only slightly because the H3O+(aq) reacts with the HCO3-(aq)