1. Television programs developed in conjunction with the marketing of toys, which was once prohibited by federal regulations, are thriving in the free market conditions permitted by the current Federal Communications Commission.
(A) Television programs developed in conjunction with the marketing of toys, which（指代不清） was（单复数不一致） once prohibited by federal regulations, are
(B) Television programs developed in conjunction with the marketing of toys, a practice that federal regulations once prohibited, is单复数不一致
(C) Developing television programs in conjunction with the marketing of toys, as once prohibited by federal regulations, is单复数不一致
(D) Federal regulations once prohibited developing television programs in conjunction with the marketing of toys, but they指代不清 are
(E) Federal regulations once prohibited developing television programs in conjunction with the marketing of toys, but such programs are
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prohibit的确是有prohibit sb/sth （from doing sth）
但也有这样的用法： a regulation to prohibit parking in the city center | 
