Marco and Alayna have a romantic relationship, but they do not experience feelings of passion for each other and are no longer connected in an intimate way. According to Sternberg, what form of love do Marco and Alayna have?

According to Sternberg, Marco and Alayna have empty love.

Explanation:

Sternberg developed a theory called the triangular theory of love, in which there are three components of love - like three vertices in a triangle. Those components are commitment, passion, and intimacy. For example, when the kind of love between two people lacks intimacy but has commitment and passion, it is called fatuous love.

Empty love is the type that has only one of the three components: commitment. There is not passion, nor intimacy. It is often the result of another type of love that has deteriorated. It's possible and probable that Alayna and Marco used to have passion and intimacy in the earlier stages of their relationship, but those feelings are now gone.