Which of the following crops is primarily grown for its high sugar content?

Beets, particularly sugar beets, are primarily grown for their high sugar content. This crop has been selectively bred over time to enhance its sugar yield, making it one of the main sources of sugar production in many parts of the world. Sugar beets are processed to extract the sugar, which is then refined for use in various food products and other applications.

In contrast, barley is primarily cultivated for its grains, which are used for animal feed, brewing, and food products, but not specifically for sugar. Peanuts are legumes that are valued for their oil and protein content rather than sugar. Sunflowers are mainly grown for their seeds and oil production, also not for sugar. Therefore, sugar beets are the clear choice when considering crops specifically grown for high sugar content.