Employees of a broker whose license has expired must

When a broker's license expires, they must stop working immediately until their license is renewed or until they obtain a new license. This is because their license is no longer valid and they are not legally allowed to perform any broker duties until they are properly certified. Option A, continue working as usual, is incorrect because it goes against the laws and regulations set forth for brokers. Option B, apply for individual licenses, is incorrect because the individual license is no longer valid if the main broker's license has expired. Option D, inform the authorities, is incorrect because the broker should already be aware of the expiration date of their license and should take action before it expires.