I say none of the answers are correct, but neither is the test item correctly stated ("saved" should be "save").
The following are suggested answers:
1. If they didn't find him in time, they wouldn't (be able to) save his life! (Situation: For example, narration for a documentary about the actions of emergency personnel.)
2. If they hadn't found him in time, they wouldn't have saved his life. (Situation: Result is known. Another possibility, which did not happen, is stated.)