Which of the following statements is NOT correct?

1 A,B and C inherited one hectare of land and they authorized X in writing to sell the land. C can revoke the authority of X without the consent of A and B.

2 P obtained a loan of P100,000.00 from A. P also appointed A as his agent to sell his car and to apply the proceeds of the sale to the loan. The agency in this case, is irrevocable.

3 P authorized A to mortgage his car and A is allowed to appoint a substitute or sub-agent. A appointed X, a notorious incomplete person as his substitute. A shall be responsible for the act of X.

4 X appointed Y as his agent with express prohibition to appoint a substitute. Y appointed W as his substitute and W carried out the agency in a manner favorable to X. The act of W is valid.

explain