25. Regarding to the concept of reduction and oxidation, which of the following statements is true?
(A) All chemical changes is accompanied by reduction and oxidation.
(B) When the atom is oxidized, the size becomes larger.
(C) The oxidizing agent is electron donor.
(D) Reduction and oxidation can occur independently of each other.
(E) Reduction and oxidation describe the gain and loss of electron(s), respectively.