Which species is likely to exhibit random dispersion? a. rushes that grow on the edges of bodies of water b. orchid plants that grow on the branches of a particular tree c. squirrels that actively defend their territory against other squirrels d. frogs that live along the edges of ponds and streams e. sweetgum, a tree species with wind dispersed seeds

The answer is E: 'Sweetgum, a tree species with wind dispersed seeds'.
The other options mention species that occupy niche environments and would therefore definitely not be randomly dispersed. Rushes and frogs would be found along the edges of water bodies, squirrels would be found within appropriate environments, which would be acorn tree forests and orchid plants also occupy a particular tree.