Biology question arteries

Hi, please can I have help on this question? I don’t understand why the answer isn’t C (the answer is A)? Don’t arteries have a smaller diameter than veins
Here is the question: https://app.gemoo.com/share/image-annotation/630962248543027200?codeId=v67N4kKGN6k8y&origin=imageurlgenerator
Thanks!

The great thing about mcq’s is you can eliminate wrong answers, and look for a difference between the remaining answers:
We rule out capillaries (single layer of endothelial cells, no collagen or elastin…). So it is not B or C.
P is artery due to large diameter and highest % elastin (for elastic recoil, artery maintain constant pressure). Since A says P = artery and D says P = vein, It is A