A.I. Explanation:

Option 1: "Potatoes are the primary source of food in many parts of the world."

Explanation: The text states that potatoes are now the staple food in most countries of Europe and America, which directly supports the conclusion that they are a primary source of food globally. This aligns with the overall theme of the text, which emphasizes the importance of potatoes in various diets.

Option 2: "The potato is a root vegetable native to Ireland."

Explanation: This option is incorrect because the text specifies that potatoes grew wild in Peru, not Ireland. While they are significant in Irish cuisine, they are not native to Ireland, making this statement factually inaccurate.

Option 3: "Most families can't afford to buy potatoes."

Explanation: The text does not mention anything about affordability. In fact, it highlights that potatoes are a staple food, implying they are widely consumed and accessible, contradicting the claim that most families can't afford them.

Option 4: "People who increased their consumption of potatoes gained more weight over time."

Explanation: This option introduces a new idea not present in the text. The passage discusses the historical significance and current status of potatoes as a staple food but does not address any health implications or weight gain related to potato consumption.