Explanation:

- Zinc has a melting point of about 419.5°C.

- Silver melts at around 961.8°C, which is quite high.

- Lead has a melting point of approximately 327.5°C.

- Tin melts at around 231.9°C, which is lower than the other options.

The melting points are crucial for various industrial applications. Comparing all these, Tin indeed has the lowest melting point. Therefore, option 4: Tin is the correct choice for the element with the lowest melting point.