What is the term Ɵ in the Kozeny Carman equation for laminar flow in packed beds?

• A. \(\frac{∆P}{L} = \frac{-180μ}{S^2 D_P^2} (\frac{(1-∈)^2}{∈^3}) ϑ_S \)
• B. Surface Area of pellets
• C. Sphericity of Pellets
• D. Void fraction
• E. Density