Which of the following is not a reason why pandemic diseases led to the destruction of early cities?

A.
Cities lacked basic sanitation, and diseases spread through sewage.
B.
Spaces were overcrowded, allowing for faster transmission of diseases.
C.
Governments were unprepared and did not have necessary evacuation plans to accommodate the sick.
D.
Medicine was undeveloped, and treatment was inadequate.

Please select the best answer from the choices provided.