It is hard to predict how changes in the climate and the atmosphere's chemistry will affect the prevalence and virulence of agricultural diseases. But there is a risk that such changes will make some plant infections more common in all climatic zones, perhaps catastrophically so. Part of the problem is that centuries of selective breeding have refined the genomes of most high- value crops. They are spectacular at growing in today's conditions but genetic variations that are not immediately useful to them have been bred out. This is good for yields but bad for coping with changes. A minor disease or even an unknown one could suddenly rampage through a genetically honed crop. Which one of the following statements best reflects the central idea conveyed by the passage?

The passage highlights the danger of relying on genetically refined crops, which, while optimized for current yields, lack the genetic diversity to cope with new or changing disease threats, especially in the context of climate change. It warns that a minor or unknown disease could catastrophically affect these crops.

A) Global climate change adversely affects the productivity of crops. While climate change is mentioned as a catalyst, the central idea is the vulnerability of genetically honed crops to diseases in the face of change, not just a general adverse effect of climate change on productivity.

B) Our total dependence on genetically honed crops entails possible food insecurity. This statement perfectly captures the core message. The passage describes how "centuries of selective breeding have refined the genomes of most high-value crops" (implying dependence) and warns that "a minor disease or even an unknown one could suddenly rampage through a genetically honed crop," leading to catastrophic outcomes, which directly translates to food insecurity.

C) Our food security should not depend on agricultural productivity alone. This is a broader statement about food security, which might be true, but the passage focuses specifically on the fragility of agricultural productivity itself due to the nature of genetically honed crops, not on other dimensions of food security like distribution or access.

D) Genetically honed crops should be replaced with their wild varieties in our present cultivation practices. The passage identifies the problem with genetically honed crops but does not propose a specific solution like replacing them with wild varieties. The central idea is the risk and vulnerability, not a prescriptive agricultural practice.