Some vascular bundles are described as open because these (a) are surrounded by pericycle but no endodermis (b) are capable of producing secondary xylem and phloem (c) possess conjunctive tissue between xylem and phloem (d) are not surrounded by pericycle.
Option B In dicot stem, cambium is present between xylem and phloem, such vascular bundles are called open. In monocot stem, the cambium is absent, such vascular bundles are called closed. Cambium are the meristematic cells which produces secondary xylem and phloem