The correct option is D Microsporangium
Pines pollinate profusely giving rise to large numbers to pollens. The pollen grains of Pines are large due to the presence of sacs or bladders, giving them a winged format. These winged pollen grains are not only easier to be identified but are carried to far away locations. These pollen grains or microgametophytes are born through meiotic division of the microsporocytes or pollen mother cells within the microsporangium.