A software bug can cause harm to a company by directly affecting its operations, reputation, user satisfaction, and financials. Option D, "When calculating the final price in a shopping list, the price of the last item is not added," describes a defect that directly impacts the core functionality of a financial transaction, potentially leading to financial loss and customer dissatisfaction. This can have severe implications for the company's credibility and revenue. Options A, B, and C describe bugs that, while potentially annoying, do not have the same direct impact on the company's core operations and financial integrity as option D.