This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to debone a trout
Remove the head of the trout.
Filleting should be done when you wish to serve only the finest cut of the fish, rather than cooking it whole. Start by cutting through the neck of the trout at the groove of the gills.

Available choices:
I. Cut across the skin, caramelizing it on one side, as it fills, then work your way up through the carcass. Because it is essential to remove the head of a trout by throwing away the head, filleting your trout from the back is preferable.
II. Angle the blade of your knife so that you're cutting toward the head rather than the body to preserve the meat. Always use a filleting knife or other sharp blade when preparing fish.
III. Go slowly at first, scraping gently as you go along so as not to irritate the skin. Rinse the flesh with cold water.
IV. Aim for where the head connects to the backbone. To safely slice trout in half, hold a pair of scissors at close to the backbone.
The answer is:
II.