​Critical Isodapane, which refers to lines of equal transport cost per unit of production, was given by:

Correct option is D

• Critical Isodapane is a concept introduced by Alfred Weber in his Least Cost Theory (1909).
• Isodapanes are lines of equal transport cost around a production center.
• Critical Isodapane is the outermost cost line where additional expenses cancel out agglomeration benefits, leading to relocation decisions.

Alfred Weber proposed the Least Cost Theory to explain the optimal location of industries based on cost minimization. The three major factors influencing industrial location are:

1. Transport Cost:

   • Industries locate near raw materials if inputs are heavy or lose weight (e.g., steel, cement).
   • If finished goods are heavier, industries locate near markets (e.g., soft drinks).

2. Labor Cost:

   • Cheap labor can offset transport costs, shifting industries toward low-wage regions.

3. Agglomeration Economies:

   • Industries cluster together to benefit from shared infrastructure, labor, and services.

Zipf  – Rank-Size Rule

• Proposed the Rank-Size Rule, which describes the hierarchical distribution of cities in a country.
• According to this rule, the second-largest city is half the size of the largest, the third-largest is one-third, and so on.
  

Losch  – Market Area Theory

• Developed the Loschian Economic Region model, which focuses on profit-maximization rather than cost minimization.
• Emphasized that industries locate where they can maximize consumer demand and profits.

Hoover – Transport and Agglomeration Economics

• Edgar Hoover studied transportation costs and industrial agglomeration but did not develop the Isodapane concept.
• His work focused on urban economies and spatial organization, complementing but not replacing Weber’s ideas.