Explanation: A leaking coupling capacitor allows DC voltage from the preceding stage's output (e.g., plate voltage in a vacuum tube amplifier) to pass to the input (grid) of the following stage. 1. **Excessive Plate Current:** This unintended positive DC voltage on the grid shifts its bias, causing the tube to conduct heavily. This results in a significant increase in plate current. 2. **Large Grid Current:** If the grid becomes sufficiently positive relative to the cathode, it will begin to attract electrons, drawing considerable grid current. 3. **Extreme Distortion and Low Gain:** With the operating point severely shifted, the amplifier tube is driven far into saturation or cutoff. It can no longer amplify the AC signal linearly, leading to clipping, severe distortion, and very little effective gain. Since all these detrimental effects are direct consequences of a leaking coupling capacitor, all the options are correct.