To solve this problem, we need to identify which group of plants has little or no secondary growth.$\newline$Let's analyze each option:$\newline \bullet$Conifers:$\newline$ - Conifers are gymnosperms that typically exhibit secondary growth.$\newline$ - They have vascular cambium that contributes to the increase in girth.$\newline \bullet$Deciduous angiosperms:$\newline$ - These are flowering plants that often show secondary growth, especially in woody species.$\newline$ - They have a vascular cambium that allows for the development of wood and bark.$\newline \bullet$Grasses:$\newline$ - Grasses are monocotyledonous plants that generally do not exhibit secondary growth.$\newline$ - They lack a vascular cambium, which is responsible for secondary growth in dicots and gymnosperms.$\newline \bullet$Cycads:$\newline$ - Cycads are gymnosperms that can show some secondary growth.$\newline$ - They have a vascular cambium, although their growth is not as pronounced as in conifers.$\newline$Based on this analysis, grasses are the plants that have little or no secondary growth.$\newline$Therefore, the correct option is Option 3: Grasses.