Please answer the following question: I'm taking a test and have to guess the right answer to the question after the article. Article: You will spend hours at the gym training your body, but do you ever think about training your brain? Here are four ways to keep your brain mentally active and healthy. Play games Your brain is a muscle just like the ones in the rest of your body. If you don't use it, you will lose it. For example, doing a crossword puzzle once a day is a good way to give the brain the exercise it needs. This kind of puzzle is good at training different areas of the brain. But remember that when doing this puzzle, you should gradually increase the complexity ; otherwise, it will become repetitive and stop being mentally challenging. Talk aloud Although it might sound strange to you, talking aloud is a great way to _ your memory. A good exercise to try is counting to 99 in threes as fast as you can. Be a team leader If you find you can do your work very easily, you should find a new task. It is important that your job should be mentally challenging. Complex jobs are often more challenging and make the brain work a little harder. Learn a language A study found that, compared with those who could speak only one language, the people who could speak two languages had a slower rate of cognitive decrease. Learning a new language is very challenging and it makes sure that different areas of the brain have their lights on. Question: Which group of people have a slower rate of cognitive decrease? Options: A: Those who don't often do crossword puzzles. B: Those who don't often count to 99 in threes. C: Those who do their work very easily. D: Those who can speak more than one language.
Answer:
D