(a) is wrong because the sentence says that liberty means the eager maintenance of that atmosphere which might require restrictions as well. (b) is wrong because if the people work only according to the law they might become good citizens but might not work to their best selves. (c) is wrong because if people do what they desire it might lead to materialist thinking which is not the best self. (d) is correct because with the growth of human personalitythe people would be their best selves.