Final answer:
If an employee presents a coworker's cost-saving idea as their own to management without credit, it constitutes plagiarism, which is unethical in the workplace.
Step-by-step explanation:
If an employee learned of a significant cost-saving idea from a coworker and then informed management of the idea without revealing its true source, then the employee would be involved in B) Plagiarism. Plagiarism in a business context involves taking someone else's ideas or work and presenting them as one's own without proper acknowledgment. This can erode trust among employees and is considered unethical behavior. Proper recognition of contributions is important for ethical decision-making and maintaining a healthy workplace environment.