When may an amateur station transmit without a control operator?
When using automatic control, such as in the case of a repeater
When the station licensee is away and another licensed amateur is using the station
When the transmitting station is an auxiliary station
Never✓الإجابة الصحيحة
الشرح
Every transmission has a control operator behind it, including automatic control: what changes under automatic control is only that the control operator need not be at the control point. Repeaters and auxiliary stations are no exception.