You will be given a definition of a task first, then some input of the task.
In this task, you're given an article, a question which often contains a blank and four options (associated with "A", "B", "C", "D"). Your task is to find the correct answer (from the given options) for the question from the given article and return one of the options from "A", "B", "C", and "D". Do not generate anything else apart from one of the following characters: "A", "B", "C", "D". There is only one correct answer for each question.

Article: The fighting against youth smoking since I took office I've done everything in my power to protect our children from harm. We've worked to make their streets and their schools safer, and to give them something positive to do after school before their parents get home. We've worked to teach our children that drugs are dangerous, illegal and wrong. Today, I want to talk to you about the historic opportunity we now have to protect our nation's children form an even more deadly threat: smoking. Smoking kills more people every day than AIDS, alcohol, car accidents, murders, suicides, drugs and fires combined. Nearly 90 percent of those smokers lit their first cigarette before they turned 18. Consider this: 3,000 children start to smoke every day illegally, and 1,000 of them will die sooner because of it. This is a national tragedy that every American should be honor-bound to help prevent. For more than five years we've worked to stop our children from smoking before they start, launching a nationwide campaign to educate them about the dangers of smoking, to reduce their access to tobacco products, and to severely restrict tobacco companies from advertising to young people. If we do these, we'll cut teen smoking by almost half over the next five years. That means if we act now, we have it in our power to stop 3 million children from smoking and to save a million lives as a result.
Question: What has the author done in his power?
Options: (A) To look after our children. (B) To clean the street (C) To clean our children (D) To protect our children from harm.
Output:
D