In basic mechanics, which of the following is best described as a compound machine made from more than one simple machine, rather than a single simple machine by itself?

Introduction / Context:
Simple machines are basic mechanical devices that change the magnitude or direction of a force, such as levers, pulleys, inclined planes, wedges, screws and wheels and axles. Many everyday tools combine these simple machines into more complex or compound machines. This question asks you to recognise that a pair of scissors is not just one simple machine but a compound machine made from more than one simple machine working together.

Given Data / Assumptions:

• We are given four objects: a pair of scissors, a lever, a ramp and a pulley.
• Each simple machine (lever, ramp, pulley) has a standard textbook definition.
• Scissors visibly combine multiple parts and cutting edges.
• We assume school-level definitions of simple and compound machines.

Concept / Approach:
A simple machine has one basic moving part or mechanism and is often used as a building block for more complex devices. A lever is a rigid bar that pivots about a fulcrum to multiply force. A ramp or inclined plane is a sloping surface that allows lifting a load with less effort over a longer distance. A pulley uses a wheel and rope to change the direction or magnitude of a force. Scissors, on the other hand, consist of two levers joined at a pivot, with each blade acting as a wedge that cuts material. Because they involve both lever and wedge action, scissors are classified as a compound machine, not as a single simple machine.

Step-by-Step Solution:
Step 1: Recall the six classic simple machines: lever, inclined plane, wedge, screw, pulley and wheel and axle.Step 2: Recognise that option B explicitly names a lever, which is one of these simple machines.Step 3: Recognise that option C, a ramp, is another name for an inclined plane, which is also a simple machine.Step 4: Recognise that option D, a pulley, is also a classic simple machine.Step 5: Analyse a pair of scissors: each handle and blade assembly acts as a lever, and the cutting edges function as wedges.Step 6: Conclude that scissors combine at least two simple machines and are therefore best described as a compound machine, not a single simple machine.

Verification / Alternative check:
Many school science books explicitly use scissors as an example of a compound machine. Diagrams show how the pivot acts as a fulcrum for two levers and how the blades act like two wedges sliding past each other to cut materials. In contrast, levers, ramps and individual pulleys are used as simple, standalone examples in these same textbooks. This consistent usage confirms that scissors are not just a single simple machine.

Why Other Options Are Wrong:
A lever by itself is one of the six basic simple machines. A ramp or inclined plane is also a simple machine used to raise loads. A single pulley is a simple machine used to change the direction of a force and sometimes provide mechanical advantage. These devices are not compound machines by themselves; they represent single basic mechanisms.

Common Pitfalls:
Students sometimes think that anything mechanical with moving parts must be a simple machine, overlooking combinations of mechanisms. Others may focus on the fact that scissors are common tools and not analyse their structure. To avoid these mistakes, always break a device down into its basic components and identify whether it uses one type of simple machine or several.

Final Answer:
A pair of scissors is a compound machine made from levers and wedges, so it is not a single simple machine.