Explanation: Overcoupling in a RADAR receiver, particularly between resonant stages like IF amplifiers or filters, refers to an excessively strong connection. When coupling is too tight, it can create unwanted positive feedback paths within the circuit. If the gain around this feedback loop is sufficient (greater than unity) and the feedback signal is in phase with the input at some frequency, the circuit will become unstable and self-oscillate. These oscillations are internally generated signals that can overwhelm legitimate target returns, effectively increasing the noise floor and desensitizing the receiver. Therefore: * **A) Improved target returns** is incorrect; oscillations degrade signal reception. * **B) Increase the range of the IAGC** is incorrect; oscillations are an instability, not an AGC function. * **C) Decrease noise** is incorrect; oscillations *add* internal noise to the receiver.