.
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 . . .