Final answer:
The unethical actions in a business setting include misleading a customer, secretly extending contracts without permission, and hanging up to prevent cancellation. Convincing a customer to sign up for an extended warranty is not inherently unethical. Ethics in business forbids practices like plagiarism, cheating, and misrepresentation.
Step-by-step explanation:
In a business setting, several actions can be considered unethical. Among the given options, misleading a customer to sign a contract, secretly extending a customer's contract without permission, and hanging up on a customer to prevent them from cancelling a service are all unethical practices as they involve deception, a lack of informed consent, and a disregard for the autonomy and rights of the customer.
In contrast, convincing a customer to sign up for an extended warranty at the time of purchase may not be unethical if the information presented is accurate and the customer is given a fair opportunity to make an informed decision. It is unethical to engage in plagiarism, cheating, and the misrepresentation of facts, and these principles extend to the realm of business conduct.
An example of a potentially ethical sales technique is the foot-in-the-door technique, where a customer who initially agrees to a small request is later presented with a larger request. While this method of incrementally increasing commitment can be applied ethically, it can become unethical if it involves manipulating or coercing the customer.