1.12.91 is the first Sunday. Which is the fourth Tuesda of December 91 ?

Answer: B. 24.12.91

1.12.91 is the first Sunday of December 91.
So, 3.12.91 is the first Tuesday of the month.
Clearly, 10.12.91,  17.12.91,  24.12.91, and 31.12.91 are also Tuesday.
So, 24.12.91 is the fourth Tuesday.