The correct option is A Pollen exine
A pollen grain is a partly germinated microspore representing the male gametophyte. It is generally globose in shape, and has two major wall layers the exine, which is the outer layer and chiefly composed of sporopollenin (an organic polymer that is resistant to oxidation and leaching), and the intine, which is the inner layer and chiefly composed of pecto-cellulose.