Explain clearly

[Sarah] Sarah has been shopping at Publix her whole life and has not considered ever shopping elsewhere. She appreciates the vast options that they provide and the convenience of its location. Recently, she has been into cooking at home and is looking into more healthy alternative food options. There are many supermarket options such as Whole Foods and Village Health Market that would cater to her needs. However, she refuses to shop anywhere else besides Publix, What term could best describe Sarah's behavior? Differential Response O Indexing Brand Loyalty Self-Selection O Heavy Half