a. phytoplankton, sedges, free-floating hydrophytes, rooted

hydrophytes, grasses and trees.

b. phytoplankton, free-floating hydrophytes, rooted hydrophytes,

sedges, grasses and trees.

c. free-floating hydrophytes, sedges, phytoplankton, rooted

hydrophytes, grasses and trees.

d. phytoplankton, rooted submerged hydrophytes, floating

hydrophytes, reed swamp, sedges, meadow and trees.

Correct option – ( b )

Explanation – primary succession in water is also known s hydrarch . Phytoplankton’s are first to appear , followed by free-floating hydrophytes, rooted hydrophytes, sedges , grasses and trees

Hence correct answer is – phytoplankton, free-floating hydrophytes, rooted hydrophytes,

sedges, grasses and trees.