Based on the research cited in the text, during the first few years of marriage marital satisfaction: 1. goes up. 2. goes up until the arrival of a first child. 3. drops. 4. fluctuates more dramatically than it does among couples who have been married for several years.

The answer is: 3 Drops.
After several years of marriage, the 'thrill' or 'passion' that make a person think they fell in love with one another tend to start to diminish.
This made them tend to reduce the effort that each couple made to court/impress each other, which lead to the drop in satisfaction.

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