Transmit "CQ" followed by the other station’s call sign
Transmit your call sign followed by the other station’s call sign
Transmit the other station’s call sign followed by your call sign✓Correct answer
Transmit a signal report followed by your call sign
Explanation
Answering a CQ puts the called station's call sign first and yours second, so the station hearing you knows immediately that the reply is for it. Reversing the order or sending CQ back is not the established practice.