Answer:
Correct Answer is option D (permanent)
Explanation:
Permanent magnet
Permanent magnet is a magnet in which magnetic properties are present even in the absence of an external magnetic field. It has its own magnetic field.
Permanent type of magnetism is present in a magnet that we use to place a photograph on the refrigerator.This permanent magnet is made up of powdered ferrite and liquid plastic. The mixture of ferrite and plastic is heated at a particular temperature and then this heated mixture is placed in a strong magnetic field. Due to this applied magnetic field this mixture is turned into a permanent magnet.
By this method of it requires less material to create a permanent magnet.
I hope this answer will help you.
