Find the odd number / letters / word from the given alternative:

Tree : Stem
Face : Eye
Chair : Sofa
Plant : Flower

The odd one out is option C. Chair: Sofa.

In all other options, the first word is a part of the second word. For example, a tree has a stem, a face has an eye, and a plant has a flower. However, a chair is not a part of a sofa. A sofa is a type of furniture, while a chair is another type of furniture.

A chair is a piece of furniture with a seat and back, typically for one person to sit on. A sofa is a long upholstered seat with a back and arms, for two or more people to sit on.