Which of the following formula is used in Falling head permeability test?

• A. Jacky‚Äö√Ñ√∂‚àö√ë‚àö¬•s formula
• B. Louden‚Äö√Ñ√∂‚àö√ë‚àö¬•s formula
• C. Darcy‚Äö√Ñ√∂‚àö√ë‚àö¬•s law
• D. Kozney‚Äö√Ñ√∂‚àö√ë‚àö¬•s formula