Let's analyze the statements based on the Indian Evidence Act, 1872:
(B) is true under Section 25, which states that no confession made to a police officer shall be proved against an accused.
(C) is true under the proviso to Section 26, which allows a confession made in police custody to be proved if it is made in the immediate presence of a Magistrate.
(D) is true under Section 27, which allows so much of a confession (even if made to police) as relates distinctly to a fact thereby discovered to be proved.
(A) is not true. Under Section 30, the confession of a co-accused can only be "taken into consideration" by the court against other co-accused. It is not substantive evidence and cannot be the sole basis for conviction. It cannot be "proved" in the same way as other evidence.