For the code segment

1.7 For the code segment
struct DOB { int date, month, year;};
struct person { char name[30];
struct DOB birthdate; } p, *ptr = &p;
Which of the following is not a valid expression to access year of birth date?
A) ptr -> birthdate.year
B) (*ptr). birthdate.year
C) ptr.birthdate.year
D) p.birthdate.year