to keep your options open or to leave your options open暂不表态；留有余地
I am keeping my options open. I have not made a decision on either matter.我保留选择权, 这两样我还没决定选哪一个。
You'd better keep your options open; you don't know what's going to happen.你最好留点选择的余地, 还不知道会发生什么事。