The correct option is B sheathing In monocots, such as wheat plants, sheathing leaf base is present. The leaf base expands and partly and wholly covers the stem.
Pulvinus leaf base is a swollen leaf base found in leguminous plants. Leguminous plants are a type of dicotyledonous plants that produce legumes or pulses and have root nodules which help in atmospheric nitrogen fixation.
Decurrent leaf base is when petiole and leaf base both become broad and continue for a distance along the stem. It covers the upper part of the node.