a. Rauwolfia serpentina
b. Santalum album (Sandalwood)
c. Cycas beddonei
d. All of the above
Answer: d. All of the above
Explanation: Endangered species are the most endangered species at a very high risk rate in the wild. This includes the IUCN animals included in the red data book. In India, species of plants like Rauwolfia serpentine, Santalum album (Sandalwood) and Cycas beddonei are endangered plant species.