Which of the following statements are NOT correct with reference to Von Thunen's Agricultural Location Theory?

A. His ideas were based on Weaver's concept of economic rent.

B. Navigable river or irrigation facilities do not have any impact on concentric land use zones.

C. In real life farmers are always economic and rational in decision making.

D. Firewood and timber production zone has lost its validity.

E. Isotrophic surfaces are universal in Asia.

Choose the most appropriate answer from the options given below: