question:  How does the writer use twins in their argument?
context: Bills are in the works in both houses of Congress to outlaw human cloning--a step urged on all governments by the pope himself. Cloning humans is taken to be either 1) a fundamentally evil thing that must be stopped or, at the very least, 2) a complex ethical issue that needs legislation and regulation. When Clinton says, "Let us resist the temptation to copy ourselves," it comes from a man not known for resisting other temptations of the flesh. It's an easy way to show sound-bite leadership on an issue that everybody is talking about, without much risk of bitter consequences. Probably almost none, because Clinton has maintained Ronald Reagan's policy of minimizing federal grants for research in human reproduction. There is nothing like banning the nonexistent to show true leadership. He also openly claims the authority to decide how people reproduce. But calling for secular governments to implement a ban, thus extending his power beyond those he can persuade, shows rather explicitly that the pope does not respect the freedom of others. So the pope's views on cloning are 1 st century rules applied using 15 th century religious thinking to a 21 st century issue. If humans have a right to reproduce, what right does society have to limit the means? Essentially all reproduction is done these days with medical help--at delivery, and often before. With in vitro fertilization, the sperm and egg are combined in the lab and surgically implanted in the womb. Less than two decades ago, a similar concern was raised over the ethical issues involved in "test-tube babies." To date, nearly 30,000 such babies have been born in the United States alone. The cloning procedure is similar to IVF. The only difference is that the DNA of sperm and egg would be replaced by DNA from an adult cell. What law or principle--secular, humanist, or religious--says that one combination of genetic material in a flask is OK, but another is not? Even if people have the right to do it, is cloning a good idea?
output:  They show that clones already exist, and are proven to grow as individuals and have their own individual rights.
options:  They show that clones already exist, and are proven to grow as individuals and have their own individual rights.  They show that like twins, clones use the same DNA to make people with shared characteristics.  They use twins to show that if clones did exist, they would grow up the same way that twins do.  They show that twins are a common occurrence, meaning cloning would not be such a new concept to introduce.