The correct answer is (b), an actionable claim.
A dower debt is a claim by a widow for a share of her husband’s property after his death. It is an actionable claim, meaning that it can be enforced through the courts.
A secured debt is a debt that is backed by collateral, such as a mortgage or car loan. The collateral can be seized if the debt is not repaid.
A preferential debt is a debt that is given priority over other debts in bankruptcy proceedings. Preferential debts include debts owed to employees, taxes, and alimony.
A mere right to sue is a right to file a lawsuit, but it is not a debt. For example, if someone injures you in an accident, you have the right to sue them for damages. However, until you actually file a lawsuit, you do not have a debt.
I hope this helps! Let me know if you have any other questions.