Answer:
a. Strong acid, strong base
Explanation:
pH = 7 , is the neutralization point , where , the concentration of Hydronium ions ( H⁺ ) becomes equal to the concentration of the hydroxide ions ( OH⁻ ) .
In case of strong acid and strong base ,
The acid and the base will dissociate completely , and will give the corresponding ions , i.e. , the ( H⁺ ) and ( OH⁻ ) , which will combine to give water , which has a pH of value 7.
In case of weak electrolytes , there wont be complete dissociation and the ions generated wont be enough to generate water of pH 7 .