Hint: Cortical bundles are water and nutrients transporting vascular systems that run through the voluminous cortex of plants. These are found in plant families of Cactaceae and Oleaceae. The vascular bundles are found scattered in the cortical region of stems.
Complete answer: The plants consist of conducting vascular tissues called xylem and phloem. These are arranged in the form of bundles. These bundles are called vascular bundles of the plant. The vascular tissue system contributes to the transport of water and nutrients. The vascular bundles are of different types based on the pattern of their arrangement. One of the types of vascular bundles is cortical vascular bundles. These vascular bundles are arranged in the cortical region of the stem of the plants. They lie scattered around the stem’s inner surface. These types of vascular bundles are specialized to replace the water lost to dry air. They are found majorly in families named Cactaceae and Oleaceae. Nyctanthes is a member of the Oleaceae family. It consists of four cortical bundles present at the rigid segments of the stem. These are inverted bundles and are the bundles of leaf trace. The cortical vascular bundles help in the transportation of water and nutrients from the voluminous cortex. The cortical bundles originate radially from the xylem and they produce shoots that pass through the cortex tangentially.
So, from the above discussion, we can conclude that option B is the right answer.
Note: The cortical vascular bundles are characteristic features of desert plants. Different species exhibit different sizes of cortical bundles. The cortical bundles function for many years till the cactus survives. The cortical bundles produce the secondary phloem in the cactus.