The correct answer is: A. All purchases of goods.
A purchase book is a book of original entry used to record all purchases of goods. It is a subsidiary ledger to the general ledger account Purchases. The purchase book is used to record the date of purchase, the name of the supplier, the quantity and description of the goods purchased, the unit price, the total amount of the purchase, and the terms of payment.
The purchase book is a valuable tool for tracking inventory and managing cash flow. It can also be used to identify trends in purchasing and to compare prices from different suppliers.
Option B is incorrect because the purchase book does not record all purchases. It only records purchases of goods.
Option C is incorrect because the purchase book does not record all credit purchases. It only records purchases of goods.
Option D is incorrect because the purchase book is used to record all purchases of goods.