D-glucose reacts with phenylhydrazine to make osazone. Moles of phenylhydrazine used for this reaction per molecule of $D$ glucose is

When glucose reacts with phenylhydrazine i.e $${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{NHNH}}_2$$

The reaction can be depicted as

Hence 3 phenylhydrazine is required to produce osazone from glucose(D)

Hence option C is the correct answer.