u/st1nky8reathEmit

This is the spec point for OCR a level biology but do I need to also be familiar with residual volume and inspiratory/expiratory reserve volume cause it's in some textbooks or only the ones the spec.

He was looking TOO GOOD with this hair down

I am really confused as to how the answer is D. Like isn't the line that Z is on inhalation since it's going up and the volume of air is increasing so how is it showing forced exhalation. Also where is forced exhalation on that graph and would vital capicity be the space between 60s and 70s or 70s and 80s?