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: Physiology
Shape of the aerial pulse is influenced by: 
Select and explain. 
A. Viscosity of blood, B. Velocity of blood, C. Aerial wall expansion, D. Cross sectional area of aery.
C: Aerial wall expansion
Answer: C: Aerial wall expansion 
Explanation: C i.e. Aerial wall expansionThe blood forced into the aoa during systole not only moves the blood in the vessels forward but also sets up a pressure wave that travel along the aeries. The pressure wave expends the aerial wallQ as it travels, and expansion is palpable as the pulse.