Which of the following is/are aquatic weeds?

Types of aquatic weeds : a.    Floating weed                                           i.         Water velvet (Azola pinnata)                                          ii.         Water hyacinth (Echhornia crassipes)                                         iii.         Water lettuce (Pistia spp)                                        iv.         Water fern (Salvinia molesta) b.    Rooted weed with floating leaves:                                           i.         Lotus (Nelumbo nucifera)                                          ii.         White water lily (Nymphaea alba) c.     Submerged weeds:                                           i.         BGA (Anabaena spp.)                                          ii.         Pond weed (Potamogeton spp.)                                         iii.         Hydrilla d.    Emergent weeds                                           i.         Typha spp                                         ii.         Ipomea spp