The sentence that requires semicolons instead of commas is:
A well-balanced diet includes root vegetables, such as carrots, dark red fruits, such as strawberries, and whole grains, such as brown rice.
This sentence contains multiple complex items that include internal commas. To clarify the separate items, semicolons should be used:
A well-balanced diet includes root vegetables (such as carrots); dark red fruits (such as strawberries); and whole grains (such as brown rice).