The correct option is
B Friday
Since 2001, 2002 and 2003 are non-leap years, each of these years has 365 days.
∴The number of days in the year after 21st January = 365 - 21 = 344 days
Number of days in 2002 = 365 days
Number of days in 2003 = 365 days
2004 is a leap year as it is divisible by 4.
So, the number of days in 2004 = 366 days
Also, the number of days in 2005 till 21st January = 21
Total number of days in total = 344 + 365 + 365 + 366 + 21 = 1461 days
Dividing 1461 by total number of days in a week
We get 5 as remainder.
Since 5 days after Sunday is Friday, Sidharth's birthday is on a Friday in the year 2005.