Sales Book
- A sales book is a subsidiary book that records all sales transactions made by a business.
- It includes details such as the date of the sale, the name of the customer, the quantity of goods sold, the sales price, and the total amount of the sale.
- It is used to keep track of all sales made by the business and is helpful in preparing financial statements and calculating profits.

Cash Book
- A cash book is a subsidiary book that records all cash and bank transactions made by a business.
- It includes details such as the date of the transaction, the nature of the transaction (whether it is a cash receipt or cash payment), the amount involved, and the balance of cash or bank at the end of the transaction.
- It is used to maintain a record of all cash and bank transactions and helps in reconciling the cash and bank balances.

Purchase Book
- A purchase book is a subsidiary book that records all purchases made by a business.
- It includes details such as the date of the purchase, the name of the supplier, the quantity of goods purchased, the purchase price, and the total amount of the purchase.
- It is used to keep track of all purchases made by the business and is helpful in preparing financial statements and calculating costs of goods sold.

All of the Above
- The correct answer is option 'D' - all of the above.
- All three books - sales book, cash book, and purchase book - are examples of subsidiary books.
- They are used to record specific types of transactions and provide a detailed record of those transactions.
- Subsidiary books are used to maintain proper books of accounts and facilitate the preparation of financial statements.
- These books are also helpful in analyzing the business's performance, tracking cash flows, and managing inventory.

In conclusion, subsidiary books such as the sales book, cash book, and purchase book are important tools for maintaining accurate records of specific types of transactions in a business. They help in organizing financial information, preparing financial statements, and analyzing the business's performance.