Instructions: 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.
Input: Article: Adding math talk to story time at home is a winning factor for children's math achievement, according to a new research from the University of Chicago. The study from psychologists Sian Beilock and Susan Levine shows a marked increase in math achievement among children whose families used Bedtime Math, an iPad app that delivers engaging math story problems for parents and children to solve together. Even children who used the app with their parents as little as once a week saw gains in math achievement by the end of the school year. The app's effect was especially strong for children whose parents tend to be anxious or uncomfortable with math. Previous research from this group has demonstrated the importance of adults' attitudes about math for children's math success. For example, a recent study found that math-anxious parents who help their children with math homework actually weaken their children's math achievement. The new findings demonstrate that structured, positive interactions around math at home can cut the link between parents' uneasiness about math and children's low math achievement. "Many Americans experience high levels of anxiety when they have to solve a math problem, with a majority of adults feeling at least some worries about math," said Beilock, professor in Psychology and author of Choke, a book about stress and performance. "These math-anxious parents are probably less likely to talk about math at home, which affects how competent their children are in math. Bedtime Math encourages a dialogue between parents and kids about math, and offers a way to engage in high-quality math interactions in a low-effort, high-impact way." Study participants included 587 first-grade students and their parents. Families were given an iPad installed with a version of the Bedtime Math app, with which parents and their children read stories and answer questions involving math, including topics like counting, shapes and problem-solving. A control group received a reading app that had similar stories without the math content and questions related to reading comprehension instead. Children's math achievement was assessed at the beginning and end of the school year. Parents completed a questionnaire about their nervousness with math. The more times parents and children in the math group used the app, the higher children's achievement on a math assessment at the end of the school year. Indeed, children who frequently used the math app with their parents outperformed similar students in the reading group by almost three months in math achievement at year's end.
Question: Bedtime Math is an iPad app that _ .
Options: (A) requires parents and children to answer reading comprehension questions (B) assesses children's math achievement and parents' nervousness with math (C) teaches children how to count, recognize shapes and solve practical problems (D) encourages children together with their parents to solve math story problems
Output:
D