"when people end a bad marriage, they are likely to experience happiness as single people than their married counterparts."

The correct answer is less. It is because when an individual experience a bad marriage who happen to end it, they are likely to feel of the things that they are likely to miss about the relationship and the struggles that the person had to face. The person who experienced this are likely to remember and reminisce the experiences that he or she encountered, making the individual more emotional and less happy.