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

How to fillet a mackerel
Place the fish onto a cutting board.
Fold down the pectoral fin (on the side of body) against the head.
Put the blade of your knife behind the folded fin, holding the knife at a slight angle.

Options:
[1]. Begin bringing the blade up, cutting through the top of the fish. You will see the skin feed through so don't cut so close to the fish's body-cut as close to the bone as possible.
[2]. Sever the head and fins from the body in one slice of the knife. When you are cutting a mackerel, do not press down with the hand holding the fish.
[3]. Slowly cut downward, without jerking, around the fin to remove the fillet. Set the brining fork on a plate.
[4]. Slide the knife across the marked shark fin, turning the fin over in the manner suggested in method one. You can also use the elbow for doing this, but it really depends on the fish.
The answer is:
[2].