Naphthalene balls derived from which of the following? 

Coal tar 

The correct answer is option 1. Coal tar.

Naphthalene balls are derived from coal tar, which is a byproduct obtained during the carbonization of coal. Coal tar is a thick, black, and viscous liquid that is produced when coal is subjected to high temperatures in the absence of air. It contains various chemical compounds, and naphthalene is one of them.

Naphthalene is extracted from coal tar and is commonly used to manufacture naphthalene balls, also known as mothballs. These small, white, crystalline balls have a distinct odor and are widely used as a household insect repellent, especially for protecting clothing and fabrics from moths and other insects.

The process of making naphthalene balls involves purifying and crystallizing naphthalene obtained from coal tar. The resulting solid white crystals are then molded into the familiar ball shape. The strong odor of naphthalene acts as a deterrent to moths and insects, making it an effective method for protecting clothes and other stored items.

In summary, naphthalene balls are a product of coal tar, and their use as mothballs is a common practice for insect repellent purposes.