Why sweet potato is the odd man out among these ginger onion?

The answer is Sweet Potato.

Sweet potato is the odd one out among ginger, onion and garlic because it is not a member of the Allium family.

Ginger, onion and garlic are all part of the Allium family, which is characterized by its pungent smell and taste.

Sweet potato, on the other hand, is a member of the morning glory family, which is known for its sweet and starchy taste.