Which one is Freundlich's equation

• A.        \[\frac{x}{m}=\log \,K+\frac{1}{n}\log \,P\]        
• B.        \[\frac{x}{m}=\exp \,(-KP)\]
• C.        \[\frac{x}{m}=K{{P}^{2}}\]
• D.        \[\log \frac{x}{m}=\log K+\frac{1}{n}\log \,C\]