The correct option is A (a) → ii; (b) → iv; (c) → v, vi; (d) → i, iii
Sepals are green outermost leaf-like floral organs, also called calyx.
Petals are coloured accessory floral organs, above sepals, also called the corolla.
Stamens are male reproductive organs. Each stamen has a slender stalk called filament and there is a terminal knoblike swelling, called anther.
Carpels are female reproductive organs. Each carpel has a basal swollen ovary, a stalk-like style and a terminal sticky part called stigma.
Thus, the correct answer is option (A), '(a) ii; (b) iv; (c) v, vi; (d) i, iii.'.