Explanation:

- Option 1: "have bought"

- This is present perfect tense, used to describe actions that occurred at an indefinite time. It’s not suitable here since the action happened five years ago, which is a definite past time.

- Option 2: "bought"

- Correct Answer

- This is past simple tense, which appropriately describes a completed action in the past at a definite time.

- Option 3: "has bought"

- This is present perfect tense, typically used for third-person singular subjects in ongoing actions. It doesn't fit here because the action occurred five years ago.

- Option 4: "buy"

- This is present simple tense, usually applied to habits or general truths, not a specific past action.