Which year will have the same calendar as that of 2005?

For every ordinary year number of odd days = 1 odd day

For leap year number of odd days = 2 odd days.

If the odd days sum=7 which implies odd days=0 then again loop starts from 1,2,3,..7.

2008 is clearly a leap year

Therefore,
2005=1 odd day(SUM=1)

2006=1 odd day(SUM=2)

2007=1 odd day(SUM=3),

2008=2 (SUM=5),

2009=1 (SUM=6),

2010=1 (SUM=7),

upto 2010 SUM OF ODD DAYS = 7 which is divisible by 7 and implies next year i.e.,2011 will have same calender as 2005 .

Option C is correct.