I can't understand＿.A.what does Christmas.B.what Christmas does mean.C.what mean Christmasmean.D.what Christmas means

I can't understand＿.A.what does Christmas.B.what Christmas does mean.C.what mean Christmasmean.D.what Christmas means
I can't understand＿.A.what does Christmas.B.what Christmas does mean.C.what mean Christmas
mean.
D.what Christmas means

I can't understand＿.A.what does Christmas.B.what Christmas does mean.C.what mean Christmasmean.D.what Christmas means
选 D what Christmas means
宾语从句,语序用陈述句形式.

D 这是宾语从句 从句用陈述句语序

D.what Christmas means

D是对的，陈述语序