Which of the following describes evidence that would best support the author's claim?
1) A study that shows that, in the U.S., spanking is becoming less and less common.
2) A story about a child who was spanked and then continued to behave badly.
3) An analysis of many studies that links spanking to children becoming more violent.
4) Data that shows that children who are spanked are more likely to spank their own children.