The correct answer is: (C) Notches in the leaf margin.
In Bryophyllum, a plant known for its ability to propagate vegetatively, adventitious buds arise from the notches along the leaf margin. These buds have the potential to grow into new plants. This remarkable ability allows Bryophyllum to reproduce asexually, even when the plant is not in flowering condition.
The process of bud formation at the leaf margins is an example of vegetative reproduction, which is advantageous for the plant's survival, especially in environments where conditions for sexual reproduction may not always be optimal.
Therefore, the correct answer is that in Bryophyllum, adventitious buds arise from the notches in the leaf margin.