Which two muscles are responsible for facial expressions related to laughter?

The Zygomaticus Major and Orbicularis Oculi are key muscles involved in the facial expressions associated with laughter. The Zygomaticus Major extends from the cheekbone to the corners of the mouth and is primarily responsible for elevating the corners of the mouth, creating the smile associated with laughter. Its action plays a significant role in expressing joy and amusement.

The Orbicularis Oculi, which encircles the eyes, contributes to laughter by producing the characteristic squinting or narrowing of the eyes that often accompanies genuine laughter or joy, commonly referred to as "crow's feet." This muscle allows for the formation of a joyful expression when one is laughing and adds to the emotional conveyance of happiness.

In combination, these two muscles effectively communicate the emotional nuances of laughter, highlighting their importance in the facial expression associated with joy. The other options involve muscles that do not directly contribute to the expression of laughter in the same way, making them less relevant to the question.