This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Main inspiratory muscle is ? 
Select and explain. 
A. Lattissimus dorsi, B. Transversus thoracis, C. Serratus anterior, D. Diaphragm
D: Diaphragm
Answer: D: Diaphragm 
Explanation: Respiratory muscles Inspiratory muscles1. During quiet breathing : Diaphragm (most impoant), external intercostal and interchondral pa of internal intercostal.2. During forced inspiration : Sternocleidomastoid, serratus anterior, serratus posterior superior, pectoralis major and minor, erector spinae, scaleni and levator costarum.Expiratory muscles1. During quiet breathing : Passive process due to passive recoil of the lungs and thoracic wall.2. During forced expiration : Internal intercostal, innermost intercostal, transversus thoracic, serratus posterior inferior, subcostalis, lattissimus dorsi and abdominal muscles (rectus abdominis, internal and external oblique and transversus abdominis).