Vitamins are chemicals essential to all cellular activity.
        
                    
             
        
        
        
Answer:
Oxytocin, a posterior pituitary hormone. (Ans A)
Explanation:
Oxytocin is known as a posterior pituitary hormone that helps to stimulate strong contractions during labor pain and help to dilate the cervix, push the baby downward and out through the birth canal, drag out of the placenta, and restrict the bleeding at the placental site. 
During the birth process, against the cervix, the pressure of the baby and then against the pelvic floor tissues helps to promote contractions and oxytocin hormone. Low levels of oxytocin hormone can cause several problems such as after birth excessive bleeding at the placenta site, contractions slow or stop and making labor time take longer, etc.
 
        
             
        
        
        
It is A. sleeping deeply.
Delta waves, like other brain waves, are recorded with an electroencephalogram (EEG) and are usually associated with the deep stage 3 of NREM sleep, also known as slow-wave sleep (SWS), and aid in characterizing the depth of sleep. 
 
        
                    
             
        
        
        
Answer:
Explanation:
The sum of the number of protons and neutrons in the nucleus is called the mass number of the isotope. The most common carbon atoms have six protons and six neutrons in their nuclei.