Which of the Following Best Explains Why a Court Will

Which of the following best explains why a court will not enforce an agreement that was created on the basis of a pre-existing public duty?

A) The performance of a public duty does not confer a benefit upon anyone.
B) As a matter of public policy, it would be undesirable if a public official with a pre-existing public duty was motivated to perform for wealthy citizens but not poor citizens.
C) Because public duties usually concern very serious matters, such as police investigations and firefighting, there is nothing that a citizen could give that would provide adequate consideration for a promise to perform a pre-existing public duty.
D) Citizens should not have to pay for services that public officials, like police officers and firefighters, perform while they are off-duty.
E) A promise by a public official is binding only if it is placed under seal.