Read the following passage and answer the items that follow. Your answers to these items should be based on the passages only.

Spanish ships in the late 16th century first brought the potato tuber from South America to Europe whereby in the early 19th century, it bad become a reliable backup to cereal crops, particularly in the cold, rain-soaked soils of Ireland. The Irish were soon almost wholly dependent on the potato as their staple food. And they were planting primarily one prodigious variety, the ‘Lumper' potato, whose genetic frailty would be cruelly exposed by the fungus 'Phytophthora infestans’. In 1845, spores of the deadly fungus began spreading across the country, destroying nearly all the Lumpers in its path. The resulting famine killed or displaced millions.

Which one or the following statements best reflects the critical message or the passage?