Question

a machine is a device that can make work easier.
there are 6 simple machines:
a lever is a bar that pivots around a fulcrum (the pivot point).
an inclined plane is a flat surface that slopes.
a wheel and axle is a wheel attached to a smaller axle. these two parts rotate together to create a simple machine.
a wedge is two inclined planes back to back.
a pulley is a grooved wheel with a cable wrapped around it.
a screw is an inclined plane wrapped around a post.
a compound machine is a device made up of two or more simple machines.
what is a device that makes work easier?
input force
a machine
friction

Explanation:

The text clearly states "A machine is a device that can make work easier."

Answer:

B. A machine