The egg of which of the following parasites consists of polar filaments arising from either end of the embryophore;
a. H. nana is the smallest cestode infecting man and also known as the dwarf tapeworm.
b. It is the only cestode which can complete its life cycle in one host.
c. The eggs are spherical or oval having two distinct membranes-outer membrane and inner embryophore. Two polar filaments arise from either end of the embryophore.