已知：typedef struct date{ int year; int month; int day;}DATE;typedef struct student{ long studentID; char studentName[10]; char studentSex; DATE birthday; int score[4]; }STUDENT;STUDENT stu1; STUDENT *pt = &stu1;则下列访问结构体变量的方法中，哪个是错误的。
A、stu1. birthday. year = 1999;
B、(*pt). birthday. year = 1999;
C、pt ->; birthday ->; year = 1999;
D、pt ->; birthday. year = 1999;