Q: 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: A few weeks ago, while I was reading the morning paper, I turned the radio up to listen to a Saturday morning talk show and I heard an old sounding gentleman, with a golden voice. He was telling whoever he was talking with something about "a thousand marbles". I was _ and stopped to listen to what he had to say ... "Let me tell you something, Tom, something that has helped me keep a good perspective on my own priorities  ." He continued, "You see, I sat down one day and did a little math. The average person lives for about seventy-five years. Now then, I multiplied 75 by 52 and I came up with 3,900 which is the number of Saturdays that the average person has in their entire lifetime. Now stick with (......) me, Tom. I'm getting to the important part." "It wasn't until I had lived through over twenty-eight hundred Saturdays that I started thinking about all this in any detail," he went on. "I got to thinking that if I lived to be seventy-five, I only had about a thousand of them left to enjoy. So I went to a toy store and bought 1,000 marbles. I took them home and put them inside a large, clear plastic container. Every Saturday since then, I have taken one marble out and thrown it away. "I found that by watching the marbles diminish  , I focused more on the really important things in life. There is nothing like watching your time here on this earth run out to help get your priorities straight. "It was nice to meet you, Tom. I hope you spend time with your family, and I hope to meet you again." You could have heard a pin drop on the radio when the old man signed off. I guess he gave us all a lot to think about. I had panned to work that morning. Instead, I went upstairs and woke my wife up with a kiss. "Come on, honey, I'm taking you and the kids to breakfast. And can we stop at a toy store while we're out? I need to buy some marbles." 
 Question: The old man started practicing the theory of "a thousand marbles"   _  . 
 Options: (A) in his twenties (B) in his fifties (C) in his seventies (D) in his eighties
A:
B