In facial expression, which muscle primarily raises the corner of the mouth during smiling?

• A. Zygomaticus major
• B. Depressor anguli oris
• C. Orbicularis oris
• D. Buccinator

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the function of each muscle listed in the options related to facial expressions.
2. Step 2: Recall that the Zygomaticus major muscle is responsible for elevating the corners of the mouth, which is the primary action during smiling.
3. Step 3: Recognize that the Depressor anguli oris muscle pulls the corners of the mouth downward, which is opposite to smiling.
4. Step 4: Know that the Orbicularis oris muscle controls movements of the lips, such as puckering, but does not raise the mouth corners.
5. Step 5: Understand that the Buccinator muscle primarily compresses the cheeks and assists in chewing, not in raising the mouth corners.