Plants having little or no secondary growth are: Conifers, Grasses, Cycads, Deciduous angiosperms

Secondary growth is defined as the growth that increases the girth or diameter and thickness of the plant as a result of the activities of primary and lateral meristem i.e. vascular cambium and cork cambium. It occurs in perennial gymnosperms and dicots such as trees and shrubs. Secondary growth is absent in monocots. Grasses belong to monocots. So, secondary growth is absent in grasses. Hence, the correct answer is option B.