A Guarantee Given by One Spouse for the Debts of Another

A guarantee given by one spouse for the debts of another is not usually thought to be one 'manifest disadvantage' for what reason?

A) A guarantee by a spouse if considered to be a manifestly disadvantageous
B) Because couple tend to be in business together - a guarantee would be for the benefit of the business
C) Because guarantees are seldom called upon so in reality it would not affect the guarantor
D) Because it would normally allow the guarantor to stay in the matrimonial home, which would be an advantage