- **Purchase of office supplies**: This is a business transaction as it involves the exchange of money for goods that are necessary for the operation of the business.
- **Withdrawal of cash by the owner for personal use**: This is not a business transaction because it involves the owner taking money out of the business for personal expenses, which does not impact the business operations directly.
- **Payment of salaries to employees**: This is a business transaction as it involves the payment of wages to employees for their work in the business.
- **Sale of products to customers**: This is a business transaction as it involves the exchange of goods or services for money with customers, which generates revenue for the business.
- **Investment in stocks of another company**: This is not a business transaction as it involves the purchase of stocks in another company, which is considered an investment activity rather than a direct business operation.