If You Want to Convince a Friend to Abandon an Attitude

If you want to convince a friend to abandon an attitude and start thinking more like you,what would be the best approach?

A) Provide information that will use fear to terrify your friend into changing his attitude.
B) Use a subtle form of ridiculous so that you friend feels bad about himself for holding his current attitude.
C) Be cautious in your approach and do not promote an idea that is too different than your friend's current attitude.
D) Present a strong argument that is diametrically opposed to what your friend currently believes.