문제 내용: 다음 글의 요지로 가장 적절한 것은?
선택지 1: ① Negotiate multiple issues simultaneously, not serially.
선택지 2: ② Avoid sensitive topics for a successful negotiation.
선택지 3: ③ Choose the right time for your negotiation.
선택지 4: ④ Don't be too direct when negotiating salary.