The correct option is B Haplodiplontic, Diplontic
In Ectocarpus, both haploid and diploid generations are prominent. The diploid generation is represented by the sporophyte which has sporangia. The sporangia undergo meiosis to produce spores. Each spore can germinate to produce a gametophyte plant. The gametophyte has gametangia that produce gametes. The gametes fuse to produce a diploid zygote. The zygote grows into a diploid sporophytic plant. Since haploid and diploid generations are equally prominent, the life cycle of Ectocarpus is diplohaplontic.
In Fucus, the prominent generation is the diploid generation. The main plant body is the sporophyte, which contains antheridia and oogonia. The antheridia and the oogonia produce sperms and ova respectively. The sperm and the ovum fuse to form the zygote, which grows to form a new sporophyte. Hence, Fucus has a diplontic life cycle.