Explanation:

- Mahr (dower) is considered a debt that the husband owes to his wife under Islamic law.

- Regarding its priority:

- Option 1: Over other creditors

- Mahr does not have priority over other creditors. Debts must be settled equally.

- Option 2: Over the other heir’s claim

- Mahr is paid before distributing inheritance, but not prioritized over other debts.

- Option 3: Both (a) and (b)

- Since both above are incorrect, this is also incorrect.

- Option 4: Neither (a) nor (b)

- This is correct. Mahr is paid as a debt, not preferable over other creditors or heirs but is settled before estate is divided.

Option:4, Neither (a) nor (b) is correct.