Identify the set of correct statements:

A. The flowers of Vallisneria are colourful and produce nectar.

B. The flowers of water lily are not pollinated by water.

C. In most of water-pollinated species, the pollen grains are protected from wetting.

D. Pollen grains of some hydrophytes are long and ribbon like.

E. In some hydrophytes, the pollen grains are carried passively inside water.

Choose the correct answer from the options given below.

To determine the correct set of statements, let us analyze each statement individually based on botanical principles of plant reproduction and pollination:

Statement A: "The flowers of Vallisneria are colourful and produce nectar."
Analysis: Vallisneria is a submerged freshwater hydrophyte that undergoes epihydrophily (pollination at the water surface). Since it relies on water currents rather than insects or animals for pollination, its flowers do not need to attract pollinators. Consequently, the flowers of Vallisneria are inconspicuous, small, colourless, and do not produce nectar or fragrance. Therefore, Statement A is incorrect.

Statement B: "The flowers of water lily are not pollinated by water."
Analysis: Although the water lily (Nymphaea) is an aquatic plant, its flowers emerge above the level of the water surface. These flowers are large, colourful, and fragrant to attract insects, or they are wind-pollinated. Thus, pollination occurs via insects (entomophily) or wind (anemophily), not by water. Therefore, Statement B is correct.

Statement C: "In most of water-pollinated species, the pollen grains are protected from wetting."
Analysis: In hydrophilous (water-pollinated) species, pollen grains are exposed to water. To prevent damage and wetting, they are typically covered by a protective mucilaginous sheath. Therefore, Statement C is correct.

Statement D: "Pollen grains of some hydrophytes are long and ribbon like."
Analysis: In several submerged marine hydrophytes like Zostera (seagrass), the pollen grains are long, needle-like, or ribbon-like. They lack an exine and are carried by water currents to reach the stigma. Therefore, Statement D is correct.

Statement E: "In some hydrophytes, the pollen grains are carried passively inside water."
Analysis: In hypohydrophilous plants (where pollination occurs below the water surface, such as in Zostera or Ceratophyllum), pollen grains are released inside the water. Having a specific gravity similar to water, they float and are carried passively by water currents until they contact the receptive stigma. Therefore, Statement E is correct.

Comparing these findings, statements B, C, D, and E are correct, while statement A is incorrect. This corresponds to the option "B, C, D and E only".