Answer:
zygomaticus Major
Explanation:
The Zygomaticus major , is one of the muscle of the human body , it is one the facial muscle responsible for smiling or laughing . Like other muscles responsible for facical expressions , the zygomaticus major is also innervated by the facial nerves.
The zygomaticus major extends from our cheekbone to the corners of the mouth.
Basically ,
When the Zygomaticus major contracts , the corner of the mouth is drawn upward , during the process of laughing.