Read the following statements and find the suitable option
a. Generally petals are green, leaf like and protect the flower in the bud stage
b. Sepals are brightly coloured to attract insects for pollination
c. If stamens in a flower remain free this is called polyandrous
d. Each ovary bears one or more ovules attached to a flattened, cushion like placenta
e. There may be a variation in the length of filaments of stamen with on flower, as in Salvinia and mustard.