Final answer:
One of the biggest mistakes in rapidly changing business environments is managers' ineffective communication skills.
Step-by-step explanation:
In rapidly changing business environments, one of the biggest mistakes managers make is having ineffective communication skills. Effective communication is crucial in any business setting as it ensures that information is transmitted clearly and accurately, which helps in decision-making, problem-solving, and collaboration. When managers have poor communication skills, it can lead to misunderstandings, conflicts, and a lack of productivity within the organization.