Which of the following describes full break-in CW (QSK)?

Full break-in CW, commonly referred to by the Q-signal "QSK", is a radio feature where the receiver recovers fast enough to allow the operator to hear incoming signals during the tiny gaps between their own transmitted dots and dashes. This allows the receiving station to interrupt or "break in" mid-transmission if necessary. Distractors often try to confuse this technical capability with procedural signals. For instance, sending the letters "BK" is a procedural way to pass the transmission back and forth, but it is not the definition of QSK. Similarly, manual send/receive switches represent the exact opposite of QSK, as full break-in requires rapid, automatic, electronic switching within the transceiver.