8. 灰交通支( gray rami communicantes )含有下列那一種神經纖維?
A.交感神經(sympathetic nerve )的節前神經纖維(preganglionic fibers )
B.交感神經(sympathetic nerve )的節後神經纖維(postganglionic fibers )
C.副交感神經(parasympathetic nerve )的節前神經纖維(preganglionic fibers )
D.副交感神經(parasympathetic nerve )的節後神經纖維(postganglionic fibers )