1. Which premise is correct?

a. Only mistakes which pertain as to the substance of the thing which is the object of the contract will invalidate consent.

b. All mistakes will vitiate consent.

c. All mistakes will invalidate the contract.

d. Errors as to account will invalidate consent.

2 Which of the following expresses a correct principle of law?

a. A threat to enforce one's claim through competent authority if the claim has no basis in fact vitiates consent.

b. There is violence when an impression is created that a grave harm will be inflicted upon one's person or property.

c. Failure to disclose facts when there is a duty to reveal them, constitutes fraud.

d. Expression of opinion always constitutes fraud.

3 What could be a valid object of a contract?

a. public property

b. government property

c. res nullius

d. forest lands