Correct Answer: stem

Solution : The correct option is the stem .

The bulb of an onion is a modified underground stem that stores nutrients for the plant's growth, and reproduction. Scales are made up of layers of modified leaves. When growth resumes, the basal plate serves as an attachment site for roots and budding shoots. This bulb adaptability allows onions to withstand adverse conditions, and employ stored resources to jumpstart new growth when conditions improve.