Final answer:
Kate violated the ethical principle of confidentiality by informing James about a potential layoff that was supposed to be confidential information. Therefore, the correct option is D.
Step-by-step explanation:
In the given scenario, the ethical principle that is violated by Kate is confidentiality. As managers within the company, both James and Kate are likely privy to sensitive information that should not be shared without proper authorization. Confidentiality is crucial in business settings to protect both the individuals and the company's interests. Discussing potential layoffs without official confirmation can lead to unnecessary distress and can compromise professional relationships. Hence, Kate's action in disclosing information that James might be laid off, which she learned from Maya, the vice president of finance, breaches the ethical duty to keep such sensitive information private.