Dikaryophase is seen in

1. Deuteromycetes
2. Basidiomycetes
3. Both $b$ and $c$
4. Ascomycetes

The correct option is C Both $b$ and $c$
Introduction to dikaryophase

Generally during fusion of cell plasmogamy is followed by karyogamy. But in some sexually reproducing Fungi, the plasmogamy is not followed by karyogamy immediately. In such cases an intermediate phase occurs and is called the dikaryophase. During this phase the cell has two nuclei.

This occurs in some of the members of Ascomycetes and Basidiomycetes.

Ascomycetes

Members of the class Ascomycetes like Claviceps, Penicillium, etc., show dikaryophase i.e., two nuclei per cell during sexual reproduction.

Basidiomycetes

During sexual reproduction, members of the class Basidiomycetes like Agaricus, Ustilago, etc., exhibit the intervening dikaryophase.

Final answer
(d) Both $b$ and $c$