Final answer:
In a Duchenne smile, the cheek muscles are pulled back, and the muscles around the A) eyes also contract.
Step-by-step explanation:
The Duchenne smile is often referred to as a genuine smile because it involves the contraction of the orbicularis oculi muscle, which causes crow's feet around the eyes. This is in contrast to a fake smile, which typically only involves the contraction of the zygomatic major muscle, pulling the lips up.
The research by Soussignan (2002) supports this, stating that the Duchenne smile, characterized by the contraction of the orbicularis oculi muscle, is associated with genuine positive emotional experiences. This phenomenon is known as the facial feedback hypothesis, which suggests that facial expressions can influence emotions.
Therefore, the correct answer is a) Eyes also contract.