Question: What happens to the 'MA memory of the ISF quantizer' when an inactive signal frame is processed in the EVS (Enhanced Voice Services) codec, as per standards for voice signal processing?
Option 1: It is updated with the previous active frame's values.
Option 2: It is set to zero.
Option 3: It is adjusted based on the smoothed quantized CNG excitation energy.
Option 4: It remains unchanged until the next active frame.
Explanation: When processing an inactive signal frame in the EVS codec, resetting the MA memory of the ISF quantizer to zero is crucial. This prevents potential noise or erroneous data from affecting voice quality during inactivity, ensuring a clean start for subsequent active frames.