The frontalis muscle is responsible for:

The frontalis muscle plays a key role in facial expression, primarily by raising the eyebrows and contributing to various expressions such as surprise and concern. This muscle is located in the forehead region and, when contracted, it elevates the skin of the forehead and helps create horizontal lines on the forehead. This action not only helps in expressing emotions but also enhances non-verbal communication, which is essential in interpersonal interactions.

Other functions listed, such as frowning and scowling, are primarily associated with different muscles, specifically the corrugator supercilii and depressor muscles. Chewing and mastication are predominantly functions of the muscles of mastication, such as the masseter and temporalis, unrelated to the frontalis muscle. Similarly, smiling and laughter involve different facial muscles, like the zygomaticus major and minor, which pull the corners of the mouth upward, rather than the frontalis. Thus, the correct answer highlights the main responsibility of the frontalis muscle in raising the brows and facilitating various facial expressions.