Consider the following excerpt regarding urban planning policy:
[A] The traditional justification for Euclidean zoning—the rigid division of land into strictly segregated residential, commercial, and industrial districts—rests on its historical success in mitigating public health crises during the early twentieth century. [B] By isolating noxious industrial activities from residential neighborhoods, early municipal planners undeniably improved urban sanitation and living conditions. [C] Consequently, Euclidean zoning became the foundational doctrine of American urban development, operating on the assumption that geographic separation inherently promotes civic well-being.
[D] However, contemporary proponents of this model fail to recognize that the socioeconomic realities of the twenty-first century have fundamentally shifted. [E] Because modern municipalities rely on interconnected knowledge economies rather than heavy manufacturing, the strict compartmentalization mandated by traditional zoning now stifles the very economic vitality it was originally designed to protect. [F] Therefore, it is imperative that municipal authorities discard rigid Euclidean frameworks in favor of dynamic, mixed-use paradigms to ensure future urban sustainability. [G] Although critics argue that mixed-use development risks increasing localized congestion, this localized inconvenience is vastly outweighed by the systemic economic stagnation inherent in geographically segregated zoning.
Identify the specific sentence that explicitly formulates the author's primary thesis. Enter only the corresponding bracketed letter.
Answer: F / f / [F] / [f] / Sentence F / Sentence f