.
B.  HINT:  the last digits of the sequence 
, 
, 
, 
, . . . 
, . . .  n = 1, 2, 3, 4, 5, 6, 7, 8, . . . 
           form a periodic sequence 7, 9, 3, 1, 7, 9, 3, 1, . . . . 
So, if you were born in 2001, then the last digit of the number 
 is 7;
    if you were born in 2002, then the last digit of the number 
 is 9;
    if you were born in 2003, then the last digit of the number 
 is 3;
    if you were born in 2004, then the last digit of the number 
 is 1;
And so on . . . . cyclically . . .