A multicelluar, filamentous alga exhibits a type of a sexual life cycle in which the meiotic division occurs after the formation of zygote. The ad adult filament of this alga has (a) Haploid vegetative cells and diploid gametangia (b) Haploid vegetative cells and diploid gametangia (c) Diploid vegetative cells and haploid gametangia (d) Haploid vegetative cells and haploid gametangia