Final answer:
Martin Seligman recommends the gratitude visit as a happiness exercise, as opposed to dwelling on the negative, suppressing emotions, or rumination, which can have negative mental health outcomes.
Step-by-step explanation:
The happiness exercise recommended by Martin Seligman is the gratitude visit. Seligman is a psychologist known for his work on positive psychology, and the gratitude visit involves writing and delivering a letter of gratitude to someone who has made a significant positive impact in one's life but has not been properly thanked. This practice contrasts with the options of dwelling on the negative, suppressing emotions, and rumination, which are not recommended as they can lead to or exacerbate issues such as depression.
It is important to note that while practices like suppression and rumination might be common for some individuals, they are generally associated with negative mental health outcomes. For example, a study by Abela & Hankin (2011) identified rumination as a vulnerability factor to depression during adolescence.