Harish was asked to identify a piece of soft iron put in a basket of 10 magnets of the same shape and size. Which is the easiest way of identifying the iron piece at the earliest?

• A.  By suspending the magnets one at a time
• B.  By conducting repulsion test using any two magnets at a time
• C.  By bringing another strong magnet near the basket
• D.  By dropping all magnets into the water