The correct option is
B Herbarium
A herbarium is a collection of pressed, dried and preserved plants mounted on paper sheets, properly labelled, systematically arranged and available for reference or study. The primary role of herbaria is to prepare pressed, dried plants, store them in cabinets, protect them from attacks by fungi and insects and offer them for study when needed.
A museum is a building used for the preservation, storage and exhibition of inanimate objects which illustrate the human or natural history. It is to educate the people about animal life and to create interest and love for animals. Extinction of animals wold disturb the balance of nature and can lead to the end of human race too.
A botanical garden is a place where plants from various groups are grown for scientific study, conservation, public education, aesthetics and recreation. A botanical garden usually houses a library, laboratory, herbarium and museum and frequently offers teaching and training facilities also.
Flora is the term used for all the plants.
Thus, the correct answer is option B.