From the words or groups of words lettered A to D, chose the word or group of words that best completes the sentence. The book is not in this locker and it ...
From the words or groups of words lettered A to D, chose the word or group of words that best completes the sentence.
The book is not in this locker and it is not in that cupboard...
Answer Details
The sentence is talking about the location of a book. The speaker has looked in a locker and a cupboard, but the book is not in either of those places.
The word that best completes the sentence is "either". "Either" is used to refer to one of two things, and can be used to indicate that neither of them are applicable or relevant. In this case, the sentence is saying that the book is not in this locker and it is not in that cupboard - so it is not in either of those places.
Therefore, the correct answer is "either".