On the basis of phylogenetic relationship, the sister group relationship exists between:

Correct option is B

In fungal taxonomy, phylogenetic relationships are determined based on molecular data, especially ribosomal RNA gene sequences and other conserved protein-coding genes. These analyses have clarified the evolutionary history of major fungal groups.
�� Why (b) Ascomycota – Basidiomycota is the Correct Answer:
· Ascomycota and Basidiomycota are the two largest phyla of the Kingdom Fungi.
· Together, they form a monophyletic clade called the Dikarya, characterized by the presence of a dikaryotic stage (n+n) in their life cycles.
· Phylogenetic analyses strongly support a sister group relationship between Ascomycota and Basidiomycota, meaning they:
· Share a recent common ancestor.
· Are each other’s closest relatives among fungi.