Which of the following provisions must a Magistrate comply as per Section 164 Cr. P.C. while recording a confession?

I. It should be recorded and signed in the manner pro¬vided in Section 281 Cr. P.C. and then forwarded to the Magistrate concerned

II. He should give a statutory warning that the accused is not bound to make a confession

III. He should be first satisfied that it is being made voluntarily

IV. He should add memorandum at the foot of the confession