Onereason_____therearesomanyFrenchwordsinEnglishisthattheFrenchruledEnglandforquiteanumberofyears．（）A.becauseB.whichC.whyD.what

　　One reason _____ there are so many French words in English is that the French ruled England for quite a number of years．（）

　　A.because

　　B.which

　　C.why

　　D.what