The correct option is A Basidiomycetes
A clamp connection is a structure formed by growing hyphal cells of certain fungi. It ensures that each cell or segment of hypha receives a set of differing nuclei, which are obtained through mating of hyphae of differing sexual types. It helps to creates genetic variation in sexually reproducing species. This is unique to Basidiomycota. This feature is used as an identification tool for this phylum. Thus, the correct answer is option A.