Correct answer is C, Creativity.
Asking yourself, What can i do to build a loyal customer base?, is an example of Creativity.
When a person in an organization is creative and wants to build a loyal customer base, he asks himself that how can he build it. He finds out ways to build a loyal customer base. He innovates, he takes out the best creativity out of him. When he is focusing on asking himself the solutions, he is basically creative who is seeking answers within himself.
With creativity you may draw customers, and with good creative ideas they will be long lasting