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The research team surveyed nearly 2, 500 parents of children aged 5—11 years. Parents completed questions about their child’s play, their general mental health and their mood. The research was carried out with two groups of parents: a group of 427 parents living in Northern Ireland and a nationally representative group of 1, 919 parents living in Great Britain.

Q: How was the research conducted?

By listing reasons.

By conducting experiments.

By making questionnaires.

By analyzing related studies.

细节理解题。根据 “The research team surveyed nearly 2, 500 parents of children aged 5—11 years. Parents completed questions about their child’s play, their general mental health and their mood. (研究团队对近2500名5至11岁儿童的家长进行了调研。家长们完成了关于孩子游戏行为、总体心理健康状况和情绪状态的问卷调查。)” 可知，研究通过问卷调查进行。故选C。