The correct option is A Roots
Aconite is obtained from the dried, tuberous root of Aconitum napellus, a perennial plant abounding in the mountains of Europe and Asia. The leaves and roots are both used but the latter is the most powerful. The alkaloid 'aconitia' or 'aconitine', a sedative poison is obtained from the root and is externally employed for neuralgic affections, producing a sensation of heat and pricking, succeeded by a feeling of numbness and constriction in the part on which it is rubbed. So, aconite is obtained from tuberous roots and not from stem, leaves and seeds. Thus, the correct answer is option A.