Question: In EVS (Enhanced Voice Services) codec, what is the primary purpose of signaling an RF_NO_DATA partial redundant frame type in a 13.2 kbps payload?
Option 1: To allocate more bits to the redundant frame for enhanced error protection.
Option 2: To utilize all available bits for primary frame coding, omitting the partial redundant copy.
Option 3: To adjust the bit-rate of the primary frame without affecting the redundant frame's size.
Option 4: To signal a switch from speech to data transmission within the payload.
Explanation: The correct answer, Option 2, aligns with the concept that signaling an RF_NO_DATA partial redundant frame type is specifically used to indicate that no partial redundant copy will be sent. This allows for the allocation of all bits towards enhancing the primary frame's coding within the specified payload, thereby potentially improving voice quality by dedicating more resources to the primary audio data.