单项选择题

—I understand you have a relative visiting you?—Yes, my______grandmother.
A.ninety-year-olds
B.ninety-old-year
C.ninety-years-old
D.ninety-year-old.

A.
A.ninety-year-olds
B.ninety-old-year
C.ninety-years-old
D.ninety-year-old.