Which of the following is true regarding the ability of persons suffering from a mental illness to enter into a binding contract?

a. Persons suffering from a mental illness have full capacity to enter into a binding contract, so long as they do not present a danger to themselves or others.
b. Persons suffering from a mental illness never have capacity to enter into a binding contract.
c. Persons suffering from a mental illness may have full, limited, or no legal capacity to enter into a binding contract, depending on the nature and extent of their mental deficiency.
d. Persons who suffer from a mental illness always have full capacity to enter into a binding contract.
e. Persons suffering from a mental illness have full capacity to enter into a binding contract, so long as they inform the other party that they are either in, or in the process of seeking, professional treatment.