Romantic relationships characterized by a couple’s complete absorption in one another and that include strong emotions and tender sexual feelings are termed:

They are called passionate love.

Explanation:

In relationships, you can experience different feelings; these feelings can be intense, lasting, or temporary.  

Some studies have described different types of love; the love of commitment, passionate love, and intimacy love.  

Passionate love is identified in the first stage of relationships, physical attraction, and feelings with vigorous-intensity are characterized as the main element. There are also other elements in passionate love, such as the need to be close to each other, the idealization of the couple, among others.  

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the answer is:

c. economic output