One weak acid (like\[C{{H}_{3}}COOH\]) and its strong base together with salt (like \[C{{H}_{3}}COONa\]) is a buffer solution. In which pair this type of characteristic is found [AIIMS 1982; CPMT 1994; MP PET 1994]

• A.                 \[pH\] and \[NaCl\]        
• B.                 \[NaOH\] and \[NaN{{O}_{3}}\]
• C.                 \[KOH\] and \[KCl\]       
• D.                 \[N{{H}_{4}}OH\] and \[N{{H}_{4}}Cl\]