Explanation:

- Statement (a): Relates to questions that a witness cannot be compelled to answer. This means a witness can choose not to provide certain answers during investigations or in court.

- Statement (b): Relates to questions that a witness cannot be permitted to answer. This protects certain communications from being disclosed, even if the witness is willing to answer.

- Option 1: Only focuses on questions that cannot be compelled (matches only statement (a)).

- Option 2: Focuses on questions that cannot be permitted (matches only statement (b)).

- Option 3: Both are relevant; a witness may neither be compelled nor permitted to divulge certain spousal communications.

- Option 4: Only focuses on permission, ignoring compulsion.