请选择ABCD'y8Z)w4B3Useven ＋ four ＝ _________,U*f,n(I*x,C/O-d7k:c-m+`-^'b)R)R
A. thirteen,U*f,n(I*x,C/O-d7k:c-m+`-^'b)R)R
B. fourteen,U*f,n(I*x,C/O-d7k:c-m+`-^'b)R)R
C. eleven,U*f,n(I*x,C/O-d7k:c-m+`-^'b)R)R
D. twelve,U*f,n(I*x,C/O-d7k:c-m+`-^'b)R)R