Most algal genera show a haplontic life cycle. Name an alga which is:
$(a)$ Haplo-diplontic
$(b)$ Diplontic

(N/A) $\rightarrow$ Haplo-diplontic life cycle is observed in $Ectocarpus$,$Polysiphonia$,and $Kelps$. In this type,the multicellular sporophyte alternates with the multicellular gametophyte.
$\rightarrow$ In $Fucus$,the main plant body is diploid (sporophytic),and it exhibits a diplontic type of life cycle.