Explanation: For a completely automatic Digital Selective Calling (DSC) acknowledgment of a Routine call and subsequent change to a suggested working channel, the *receiving station's* DSC equipment must be specifically configured for automatic response. Modern DSC radios can be programmed to automatically acknowledge low-priority calls and direct the radio to the agreed-upon working frequency without human intervention, ensuring unattended operation. Option A is incorrect because DSC calls are transmitted on VHF Ch-70, not Ch-16 (which is for voice distress and calling). Monitoring Ch-16 would not allow for receiving the DSC call, nor would it facilitate an automatic DSC acknowledgment. Option B is incorrect as the receiving station will only switch to and monitor the suggested working frequency *after* the DSC call has been acknowledged and the channel change command processed. Option C is incorrect because, while manual acknowledgment is an option, DSC systems are capable of, and often configured for, automatic acknowledgment of routine priority calls, especially when unattended.