What Should a Firm Do to Create a Sustainable Advantage

What should a firm do to create a sustainable advantage based on product excellence?

A) Maintain strong relationships with suppliers and retailers
B) Undertake advertising and brand-building campaigns to reinforce brand positioning
C) Situate stores in all busy shopping areas and malls in a city
D) Develop a script for customer service so that all customers have a consistent experience
E) Introduce customer loyalty programs to retain existing customers