The correct option is
D a - Rhizome
b - Bulbil
c - Offset
When a new plant grows from a fragment of the parent plant or a specialized reproductive structure (other than flower), then this is called vegetative propagation. These specialised structures are called vegetative propagules. Vegetative propagules include structures like runner, rhizome, sucker, tuber, offset, bulb, buds which are capable of giving rise to new offspring.
In ginger vegetative propagation occurs by rhizome. It is a horizontal underground stem that gives out both shoots and roots.
In Agave the vegetative propagule is the bulbil. It is a small bulb-like structure produced in the place of a flower or in a leaf axil, and having the ability to develop into a new plant.
In water hyacinth vegetative propagation occurs by offset. It is a type of sub-aerial stem. Offset is also referred to as the runner of the aquatic plants. It originates from the leaf axil and runs horizontally, bearing a rosette of leaves above and adventitious roots below its tips.