Final answer:
Using company resources for personal gain is generally considered an unethical act.
Step-by-step explanation:
The unethical act among the given options is Option C: using company resources for personal gain. This refers to the misuse of company assets, such as using office supplies or equipment for personal use, or taking advantage of work time for personal matters. This act goes against ethical behavior as it violates the trust and integrity expected in a professional setting.