Intercostal nerve is a branch of ?

Ans. is 'c' i.e., Ventral rami of thoracic spinal nervesVentral rami of upper 11th thoracic spinal nerves are known as intercostal nerves and ventral ramus of T12 is known as subcostal nerve.Upper six intercostal nerves supply thoracic wall whereas lower five intercostal nerves and subcostal nerve supply thoracic and anterior abdominal walls and hence known as thoracoabdominal nerves. Upper two intercostal nerves also supply the upper limb.Thus only 3rd to 6th are called typical intercostal nerves.