Which one of the following enzymes is not necessary for obtaining protoplasts for their somatic hybridization?

The correct option is B Primase
Isolation of protoplasts is readily achieved by treating cells/tissues with a suitable mixture of cell wall degrading enzymes. Usually, a mixture of pectinase or macerozyme (0.1-1.9%) and cellulose (1-2%) is appropriate for most plant materials. Hemicellulase may be necessary for some tissues.