Explanation:

Kirayat is an Indian herb with scientific name Andrographispaniculata. As an Ayurveda herb it is also known by the name Kalamegha or dark cloud. It one of the most bitter herb called by the name Maha-tikta that is kind of the bitters in NE. Recently Kirayat was in news as the National Centre for Cell Science, Pune has extracted Andrographolide which has been shown as inhibiting tumour growth in both skin and lung cancers. At present the research is conducted in-vivo in mice and is said to have a potential cure for melanoma in human beings. Hence, answer is B.