According to the author (in this preface) the book is
A
the original version of his Cambridge lectures
B
a revised version of his Cambridge lectutres
C
an imitation of his Cambridge lectures
D
a negation of his Cambridge lectures
E
an authentic version of his Cambridge lectures
Verified Correct Answer: B.
Grammar & Contextual Explanation
In the first line, the author clearly states: "This book consists of lectures given by me at Cambridge. Though they have been largely rewritten..." This shows that the content of the book is based on the lectures but has been "largely rewritten" — meaning revised.
Source: Myschool Past Questions Archive (Record #15251)