Candace bought a house and decided to install new flooring. She went with an ash$-$coloured hardwood floor, which cost $$2500.$ A week after choosing the flooring, she called her contractor in a panic to ask how hard it would be to change her flooring selection because ash might not be as uplifting a flooring colour as she had first thought. Candace is experiencing what type of postpurchase sentiment$?$

a$.$ Cognitive dissonance

b$.$ Extensive decision making

c$.$ Decision confirmation

d$.$ Involvement