Explanation: Glint refers to the apparent shifting or fluctuating position of a RADAR return from a complex target or clutter, particularly when an MTI (Moving Target Indication) filter is involved. MTI filters are designed to suppress stationary clutter by comparing successive RADAR pulses and filtering out signals that have no Doppler shift. An improperly functioning MTI filter (A) can cause glint. If the filter fails to accurately cancel stationary clutter, or if there are imperfections in its phase or amplitude cancellation across pulses, residual clutter will be passed through. This residual clutter, due to its incomplete cancellation and slight variations from pulse to pulse, can appear to "shift" or fluctuate in position on the display, leading to the phenomenon known as glint. Memory failure (B) is too general and not a direct cause of this specific clutter behavior. Interference from electrical equipment (D) typically manifests as noise or spurious signals, not as a systematic shifting of legitimate clutter returns due to processing errors.