Final answer:
Option (2), Support for the death penalty in the United States has decreased in recent decades, attributed to declining violent crime rates, wrongful execution revelations via advanced DNA testing, and the abolition of capital punishment in multiple states.
Step-by-step explanation:
According to the provided text, support for the death penalty has decreased over the last few decades. This trend is due in part to an overall decline in violent crime, advancements in DNA testing technology which revealed wrongful executions, and the subsequent abolition of capital punishment in several states since 2007. As of 2015, nineteen states and the District of Columbia have abolished the death penalty for new cases.