To indicate a communication is complete and no response is expected, what should a transmitting employee say?

When communicating in a context where clarity and protocol are vital, the term "Out" is specifically used to convey that a communication is complete and that no further response is required. This term clearly signifies the end of the exchange and ensures that the receiving party knows the conversation has concluded.

Using "Out" is consistent with the standardized communication practices in rail operations, which aim to minimize misunderstandings. The other options, while potentially understood as concluding phrases in casual conversation, do not hold the same level of formality or clarity in operational contexts. Thus, "Out" is the preferred choice for formally indicating the end of communication without expectation of a reply.