Question: What is a prerequisite for a User Equipment (UE) to support uplink HARQ ACK Feedback in RRC_CONNECTED mode when operating in coverage enhancement?
Option 1: Support for LTE TDD mode
Option 2: Support for ce-ModeA-r13
Option 3: Capability for downlink MIMO
Option 4: Activation of Carrier Aggregation
Explanation: For a UE to support uplink HARQ ACK Feedback in coverage enhancement scenarios, it must also support ce-ModeA-r13, indicating this mode's support is a prerequisite for the mentioned feedback capability in wireless communications.