Correct Answer - Option 3 : Saturday
The 4th day after the 21st of the month will be 25th of the month.
The number of days between the 3rd and the 25th day = 22 days
22 days = 3 weeks and 1 day
The three week period will start from the 4th of the month which is Saturday and the three week period will end on a Friday. The next after Friday would be a Saturday.
Hence, the 25th of the month will be a Saturday.
