Dalbergia sissoo (Indian rosewood) can be propagated vegetatively through stem cuttings, root cuttings, and root suckers. Among the options, intact roots (option C) are correct because they produce root suckers that develop into new plants. Root cuttings are a common propagation method for this species. Options A, B, and D are incorrect - flower buds cannot vegetatively propagate, stem cuttings are not the primary method listed, and leaf margins are not used for Dalbergia propagation.