What is the focus of the book "Xi: A Study in Power" by

Four letter-clusters have been given out of which three are alike in some manner and one is different. Select the odd one.

Four letter- clusters have been given, out of which three are alike in some manner, while one is different. Choose the odd one.

Four number-pairs are given, three of them are alike in a certain manner and one is different. Choose the different number-pair.

Find the odd one out.

Four letter-clusters have been given out of which three are alike in some manner and one is different. Select the one that is different.

Select the option in which the numbers are related in the same way as are the numbers of the following sets.  

(43, 74, 36)

Four letter- clusters have been given, out of which three are alike in some manner, while one is different. Choose the odd one.

Four pairs of numbers have been given, out of which three are alike in some manner, while one is different. Choose out the odd one.

Three of the following words are alike in a certain manner and one is different. Select the odd word out.

Three of the four words are alike in a certain way and one is different. Pick the odd one out.