The correct answer is: A. Minor
A minor is a person who is under the age of majority, which is typically 18 years old. In most jurisdictions, minors are not considered to have the capacity to enter into contracts. This is because minors are considered to be too young to understand the nature and consequences of entering into a contract.
A major is a person who is over the age of majority. In most jurisdictions, majors are considered to have the capacity to enter into contracts. This is because majors are considered to be old enough to understand the nature and consequences of entering into a contract.
A person of sound mind is a person who is not mentally ill or incapacitated. In most jurisdictions, a person of sound mind is required to have the capacity to enter into a contract. This is because a person who is mentally ill or incapacitated may not be able to understand the nature and consequences of entering into a contract.
A person who is not disqualified under law is a person who is not prohibited by law from entering into a contract. For example, a person who is a convicted felon may be prohibited from entering into certain types of contracts.
In conclusion, the correct answer is: A. Minor.