The rate at which blood flows through the human body can change in response to multiple factors. Which statement describes one of these factors and the effect it has on blood flow?

A. The narrowing of blood vessels increases pressure and leads to faster blood flow

B. High blood viscosity increases the resistance in the blood vessels and leads to faster blood flow.

C. Low blood pH decreases the rate of diffusion through the blood vessels and leads to slower blood flow.

D. The changing of the shape of red blood cells to a crescent shape decreases resistance and leads to faster blood flow.

Explain why this is the correct answer and why the other ones are wrong: