Find the odd one out in each group and give reasons for your choice.

The correct option is D

Potato

The correct option is D:
Explanation for the correct option:

1. The parts of plants are modified to perform various functions apart from the main function. These are known as modifications.
2. The excess food produced in the plants is stored in the underground stem, these stems are modified stems.
3. A potato is such an underground stem that is modified to store excess food produced by the plants

Explanation for incorrect options:
Option A:
Sweet potatoes are modified roots that are meant to store food produced in excess by the plants.

Option B:
Radish is a modified root used for the purpose of storing food produced by plants.

Option C:
Carrots are the result of the modification in the root that is involved in the storage of food.

Final answer: Potatoes are a stem modification.