Explanation:

- Valid acceptance:

- Acceptance is generally effective when communicated to the offeror.

- If the offeree accepts without knowing about the offeror’s death or insanity, it is often still considered valid.

- The law aims to protect the interests of the unaware party.

- Correct Answer: Option 1 - Valid acceptance.

- Not valid:

- An acceptance might be deemed invalid if the offeree was aware of the offeror's death or insanity.

- Knowledge of such facts typically voids an agreement.

- Illegal acceptance:

- The term "illegal" implies a violation of law, which isn't applicable here.

- This doesn't describe the acceptance in this case.

- Fraudulent acceptance:

- Fraud implies intentional deception, which isn't inherent in accepting unknowingly.

- Therefore, it's not applicable in this context.