Flowers without petals are pollinated by:

Correct answer: (a) Wind

Explanation

Flowers that have no petals, or only small, dull ones, are usually wind-pollinated (anemophilous). Such flowers do not need to attract insects or birds, so they have no bright petals, scent or nectar. Instead they make large amounts of light, dry pollen, and their stigmas are large and feathery to catch it.

Examples are grasses, wheat, rice, maize and many trees. Insect-, butterfly- and bird-pollinated flowers usually have bright, showy petals.