The Glass House Mountains in Queensland, Australia, were sighted in 1770 by the English navigator Captain James Cook, [by whom they were named supposedly because its] sheer we rocks glistened like glass.
A. by whom they were named supposedly because its
B. by whom they were named supposedly and their
C. naming them supposedly since their
D. who so named them supposedly because their
E. who so named it since supposedly their
D为正解，og在C的解释中有这么句话：”since”loses the important causal logic of the sentence 请问在gmat中since不能表达原因，解释因果关系吗？ | 
