The answer you are looking for is B.
Answer:
I would be the extension of the trunk
Explanation:
The erector spinae muscle extends the vertebreal column. [1] It is formed of 3 muscles and its fibers run more or less vertically throughout the lumbar, thoracic and cervical regions. It lies in the groove to the side of the vertebral column. In cervical region it is covered by nuchal ligament and in thoracic and lumber region by thoracolumbar fascia.
Answer: menstruation
Explanation: the process in a female of discharging blood and other materials from the lining of the uterus at intervals of about one lunar month from puberty until menopause, except during pregnancy.
