To answer this question, the user needs to be aware of the Booker Prize, which is a literary prize awarded each year for the best original novel written in the English language and published in the UK. The user also needs to know that the 'Booker of Booker' prize is awarded to the best book among the winners of the previous 25 years of the Booker Prize.

Now, let's go through each option to determine which book was awarded the 'Booker of Booker' prize:

A. God of Small Things: This book was written by Arundhati Roy and won the Booker Prize in 1997. It was not awarded the 'Booker of Booker' prize.

B. Midnight's Children: This book was written by Salman Rushdie and won the Booker Prize in 1981. It was awarded the 'Booker of Booker' prize in 1993 to celebrate the 25th anniversary of the Booker Prize.

C. The White Tiger: This book was written by Aravind Adiga and won the Booker Prize in 2008. It was not awarded the 'Booker of Booker' prize.

D. Life of Pi: This book was written by Yann Martel and won the Booker Prize in 2002. It was not awarded the 'Booker of Booker' prize.

Therefore, the correct answer is:

The Answer is: B