Which of these is not a simple machine?

Answer: Option A

Any of the basic mechanical devices for applying a force are called simple machines.
There are 6 basic simple machines; the lever, the wheel and axle, the inclined plane, the wedge, the pulley, and the screw. Several of these simple machines are related to each other. But, each has a specific purpose in the world of doing work. A pair of scissors is not a simple machine.