The last day of a century cannot be.

There are 5 odd days in every 100 years. So, 'Friday' is the last day of the first century.

There are 10 odd days in a year, which equals 3 odd days.

So, 'Wednesday' is the last day of the second century.

There are 15 odd days in 300 years, which equals 1 odd day.

So, 'Monday' is the last day of the third century.

There are 6 odd days in 400 years.

So, 'Saturday' is the last day of the fourth century.

We can see that the concluding day of a century cannot be Tuesday, Thursday, or Saturday since the sequence is retained in succeeding cycles.

Hence, the correct answer is option D, i.e.,Tuesday