Extra exam question E2C10

WhyDX stations often transmit and receive on different frequencies because some responding stations may be barred from the DX station's exact frequency, splitting keeps the calling stations separated from the DX station, and it improves overall operating efficiency. DX stations often work split, transmitting on one frequency and listening on another, for several reasons at once: some responding stations may be barred from transmitting on the DX station's exact frequency, splitting separates the flood of calling stations from the DX station's own transmit frequency, and it generally improves operating efficiency by reducing interference during the exchange, answer D. Since each of those is a genuine reason DX stations split their transmit and receive frequencies, no single one alone is the complete answer.