The Law Makes Individuals Suffering from a Mental Illness Lack

The law makes individuals suffering from a mental illness lack capacity to enter into contracts because:

A) the mentally impaired tend not to vote in large numbers.
B) those with a mental illness would be at a disadvantage in their ability to protect their own interest in bargaining.
C) an individual cannot be on public assistance and be legally competent to enter into a contract.
D) there is fear that those with a mental illness would manipulate and harm those that they would enter into contracts with.