E4C13 - Amateur Extra Class

E4C13 : What is reciprocal mixing?
A Two out-of-band signals mixing to generate an in-band spurious signal
B In-phase signals cancelling in a mixer resulting in loss of receiver sensitivity
C Two digital signals combining from alternate time slots
D Local oscillator phase noise mixing with adjacent strong signals to create interference to desired signals
Correct Answer: Local oscillator phase noise mixing with adjacent strong signals to create interference to desired signals