Final answer:
Two coworkers who appeared to dislike each other but are now getting married exemplify the defense mechanism of reaction formation, where individuals replace unacceptable feelings with their opposites. Reaction formation is a defense mechanism where a person expresses feelings, thoughts, and behaviors opposite to their inclinations.
Step-by-step explanation:
The scenario where two coworkers seemed to hate each other and now they are getting married showcases a psychological phenomenon known as reaction formation. This is an ego defense mechanism where a person confronted with anxiety replaces unacceptable urges or behaviors with their opposites. In this case, the two coworkers expressed negativity and animosity towards one another, which, instead of being genuine, may have been a cover for their true feelings of attraction and affection. This behavior is the exact opposite of their true feelings, illustrating the reaction formation defense mechanism.