Of the options that you have offered here, the best answer is “order qualifiers.” The other terms are not good fits for the definition you have given.
Core competencies do not have to do with the characteristics of a product that consumers expect. Instead, core competencies have to do with what a company does best. The basic heart of a company’s business is its core competency. Companies should not outsource operations in their core competencies and should not lose their ability to be at the cutting edge in those competencies.
Minimum attributes is a term that usually refers to job qualifications. There are said to be minimum attributes that would make a person qualified for a given job.
A distinctive competency is something that makes a firm unique. This is an ability that the firm has that distinguishes it from other firms.
Order winners are the qualities of a product that make a consumer want to buy that product. It is not the minimum that they will accept. Instead, it is the factor that determines what they buy.
This leaves order qualifiers. These characteristics make a product qualified to be ordered. In other words, a customer will not ever order a product without those characteristics. This makes order qualifiers the best answer to your question.