Final answer:
A washing machine is an example of a compound machine, as it is composed of multiple simple machines working together.
Step-by-step explanation:
In order to determine which options represent compound machines, we need to understand that a compound machine is a combination of two or more simple machines. Simple machines include levers, wheels and axles, pulleys, wedges, and screws, among others.
In this case, the answer is c. a washing machine. A washing machine is composed of multiple simple machines, such as gears, levers, and pulleys, working together to perform its function.
The other options do not consist of multiple simple machines. An a. car utilizes complex systems and mechanisms, but it does not meet the criteria for a compound machine. A b. handheld screwdriver is a simple machine, specifically a screwdriver, and does not contain multiple simple machines. Lastly, a d. watch is a complex device but does not fit the definition of a compound machine.