A) Can spread populations only by rhizome extension
B) Are flowering plants that are pollinated by flying insects at the time of low tide
C) Are flowering plants that are fertilized by pollen that is spread by water currents
D) Are flowering plants with self-fertilization only

A) Have their lower depth limited strictly by light
B) Have their lower depth limited by herbivore pressure by fish grazing
C) Can live at great depths, as much as 10 m
D) Cannot grow in soft sediment such as mud because the pore waters lack oxygen

A) Are rather indigestible so only a restricted number of herbivore species can subsist on them
B) Are always strongly controlled by grazing by herbivores
C) Are digestible by invertebrates but not vertebrates
D) Tend to grow right up to the edge of patch reefs in the Caribbean