Shamita's birthday was on 15 March 2020, which was a

Solution

March has 31 days, April has 30 days, and May has 31 days. Total days from March 15 to May 31: = 16 days (March) + 30 days (April) + 31 days (May) = 77 days Now, since 77 is divisible by 7 (7 days in a week), the day of the week will remain the same. Shamita's birthday was on a Sunday. Adding 77 days (which is a multiple of 7) to a Sunday will still be a Sunday. So, Shamita's husband's birthday, on May 31, 2020, would also fall on a Sunday. Thus, the correct answer is option 2. Sunday.