请教大全中的一个问题

The increased popularity and availability of televisions has led to the decline of regional dialects, language variations which originate from diverse ethnic and cultural heritages and perpetuated by geographic isolation.

(A) which originate from diverse ethnic and cultural heritages and perpetuated

(B) that originated from diverse ethnic and cultural heritages and perpetuated

(C) originated from diverse ethnic and cultural heritages and perpetuated

(D) originating from diverse ethnic and cultural heritages and perpetuated

               (E) originating from diverse ethnic and cultural heritages and perpetuating

正确答案是D，难道不应该是B吗？请教高手