The correct option is C Wednesday
1600 years contain 0 odd day, 300 years contain 1 odd day. Also, 83 years contain 20 leap years and 63 ordinary years and therefore (40+0) odd days i.e., 5 odd days.
∴ 1983 years contain (0+1+5) i.e., 6 odd days.
Number of days from Jan. 1984 to 31st Oct. 1984
=(31+29+31+30+31+30+31+31+30+31)
=305days=4odd days
∴ Total number of odd days =6+4=3 odd days.
So, 31st Oct, 1984 was Wednesday.