What Would Kant Say About the Case of Breaking a Deathbed

Multiple Choice

What would Kant say about the case of breaking a deathbed promise?

A) We are justified in breaking a promise if necessary to promote our self-interest.
B) We are justified in breaking a promise if necessary to promote the happiness of everyone involved.
C) It is permissible to break a promise only if necessary to uphold a more stringent moral principle, such as cause no harm.
D) The maxim permitting you to break a promise cannot be universalized, and hence breaking your promise would be immoral.