What is Poiseuille’s law?

• A. η=\(\frac{πpr^4 t}{8Vl} \)
• B. η=\(\frac{πpr^4 t}{16Vl} \)
• C. η=\(\frac{πpr^4 t}{32Vl} \)
• D. η=\(\frac{3πpr^4 t}{8Vl} \)