A screw has 4 threads per centimeter and a circumference of 2 centimeters. What is the mechanical advantage of the screw?

To calculate the mechanical advantage of a screw, we can use the formula:

\[
\text{Mechanical Advantage} (MA) = \frac{\text{Circumference}}{\text{Pitch}}
\]

Where:
- The **circumference** is the distance covered in one complete revolution of the screw.
- The **pitch** is the distance between adjacent threads.

In this case:
- The circumference of the screw is given as \(2\) centimeters.
- The pitch can be calculated based on the number of threads per centimeter. Since the screw has \(4\) threads per centimeter, the pitch is the reciprocal of that:

\[
\text{Pitch} = \frac{1 \text{ cm}}{4 \text{ threads}} = 0.25 \text{ cm}
\]

Now, substituting the values into the formula for mechanical advantage:

\[
MA = \frac{2 \text{ cm}}{0.25 \text{ cm}} = 8
\]

Thus, the mechanical advantage of the screw is \(8\).

The correct answer is \(\boxed{8}\).