Introduction:
A simple machine is a device that helps to make work easier by changing the force or direction of the applied force. There are six types of simple machines, including the lever, pulley, wheel and axle, inclined plane, wedge, and screw. Among these, the correct answer is option 'B', which states that a simple machine can do more work with less effort.

Explanation:
A simple machine can be understood as a tool that allows us to apply a smaller force to overcome a larger force or do more work with less effort. Let's explore this concept further:

1. Levers:
A lever is a simple machine that has a rigid bar (such as a seesaw) that rotates around a fixed point called a fulcrum. It can help us lift heavy objects with less effort by increasing the distance from the fulcrum to the applied force. For example, using a crowbar to lift a heavy rock.

2. Pulleys:
A pulley is a simple machine that consists of a grooved wheel and a rope or cable. It can change the direction of the force and make it easier to lift heavy objects. By using multiple pulleys, we can reduce the amount of force needed to lift an object. For example, using a pulley system to lift a bucket of water from a well.

3. Wheel and Axle:
The wheel and axle is a simple machine that consists of a wheel attached to a rod or axle. It allows us to exert less force to move objects by increasing the distance between the applied force and the center of the wheel. Examples of the wheel and axle include a bicycle wheel or a doorknob.

4. Inclined Plane:
An inclined plane is a simple machine that is a flat, sloping surface. It allows us to exert less force over a greater distance to move objects vertically or horizontally. For example, using a ramp to push a heavy object up to a higher level.

5. Wedge:
A wedge is a simple machine that is thick at one end and tapers to a thin edge at the other. It can be used to split, lift, or hold objects in place. By using a wedge, we can apply less force to perform these tasks. Examples of wedges include knives and axes.

6. Screw:
A screw is a simple machine that consists of an inclined plane wrapped around a cylindrical post. It allows us to exert less force to hold objects together or to move them. For example, using a screwdriver to tighten a screw.

Conclusion:
In summary, a simple machine can do more work with less effort. By utilizing the principles of simple machines, we can overcome larger forces, change the direction of forces, and make our daily tasks easier.