Answer:
The correct answer is - tubers.
Explanation:
In a crop plant, there are certain parts that are rich in different macronutrients and can be a good source of the particular nutrient. Grains provide starch and other sugar for the energy and calories in a crop, however, roots and tubers are also a good source of carbohydrates in a crop.
Tubers are the enlarged part stored by plants as stored nutrients to provide energy and nutrients in unfavourable conditions. These are generally a good source of carbohydrates