Pharyngeal constrictor muscles (superior, middle and inferior)
The pharyngeal constrictor muscles are a group of muscles that form the lumen of the pharynx. After you swallow, an act that you have control, it starts a involuntary contraction by these muscles to propel the bolus downwards.
Answer:
B
Explanation:
Environmental factors don't determine all of your genetics traits but they do influence them.
What are you trying to ask?
The correct answer is birth.
At birth, females infants on an average appear to have a more developed central nervous systems compared to males. This is apparent because female infants shower higher levels of responsiveness to stimuli such as sounds, touch and faces. Additionally, female infants typically acquire linguistic abilities and vocalize earlier than male infants.