The medicinal herb brought by Hanuman from the Dronagiri mountains is called Sanjeevani. This life-restoring herb was needed to save Lakshmana, who had been critically wounded by Indrajit's spear during the battle. The name 'Sanjeevani' literally relates to bringing back life or prolonging life, which is exactly what the herb did - it revived Lakshmana from near death. The other options are incorrect names or variations.