Explanation:

- The original sentence is: "He promised to deliver the goods yesterday, did he?"

- Option 1: didn't he

- This option is the correct tag question for the sentence. The rule for tag questions is that if the main clause is positive, the tag should be negative. Since "He promised" is positive, "didn't he" is the right negative tag.

- Correct Answer

- Option 2: would he

- "Would he" is an inappropriate tag in this context. It doesn't relate to the verb "promised."

- Option 3: No substitution

- Keeping "did he?" would not be grammatically correct.

- Option 4: isn't it

- "Isn't it" refers to "it," but there is no "it" to refer to in the sentence.