Gladiolus is propagated through:

Correct option is B

The correct option is (c) corms. 

Gladiolus plants produce underground storage organs known as corms for vegetative propagation and food storage.

·         A corm is a short, vertical, swollen underground stem with nodes and internodes, covered by a protective tunic (papery covering).

·         This structure allows the plant to survive adverse conditions and produce new plants (cormlets or daughter corms). 

Why other options are incorrect

• A. Stem: While a corm is a modified stem, the general term "stem" is not specific enough to describe the specialized underground reproductive organ used for propagation.
• B. Bulb: A bulb, such as an onion, has a short stem base but primarily stores food in its fleshy leaf scales, which is structurally different from a corm's solid, starchy stem tissue.
• D. Slips: Slips are a method of vegetative propagation usually associated with plants like sweet potatoes, where buds arise at the point between the root and the stem at the base. They are not the propagation material for gladiolus.