The part of a textbook that states the authors purpose is a. table of contents b. bibliography c. preface/introduction d. index

The part of a textbook that states the author's purpose is the Preface/introduction

Explanation:

The first part of a textbook is the preface or introduction, the preface is more accurate in terms of stating the author's purpose, but they both are considered quite similar for many, then the introduction can also state the purpose even when it sometimes forms part of the rest of the chapters as an opening to the whole.

brazil   is on the caost

he was looking for nothing because this question had no complete sentence.