The correct option is C ‘a’ - eyes - vegetative propagation in potato
The part labelled as ‘a’ in the diagram are eyes of the potato tuber. Eyes are vegetative propagules of potato through which vegetative propagation occurs in potato. New potato plants can grow from these eyes. Vegetative propagules are the units of vegetative propagation. This vegetative propagation is a type of asexual reproduction that occurs in plants in which new plant grows from a part of the parent plant or a specialized reproductive structure called vegetative propagule.
Bulbil is the vegetative propagule of Agave. It is a small bulb-like structure produced in the place of a flower or in a leaf axil.
Adventitious bud is the vegetative propagule of Bryophyllum. They arise from the notches present at the margins of Bryophyllum leaves.
Rhizome is a vegetative propagule of banana and ginger. It is a horizontal underground stem that is capable of giving rise to new plants.