Gladiolus is generally propagated by

Answer: Option B

Gladiolus is generally propagated by Corm.
Gladiolus is propagated by corms, the underground storage organs - which are sometimes wrongly called bulbs and cormels. The cormels of the first year would be normally of very small size and would not yield any flowers.
During the growth cycle of the gladiolus, the main corm sprouts small cormlets, which are the primary reproductive structure of the plant.