The correct option is C Polymerase
The enzyme required for joining two molecules of nucleotides is a polymerase. It can be a DNA polymerase, that polymerises deoxyribonucleotides or an RNA polymerase, which polymerises ribonucleotides.
Lyases are a group of enzymes which catalyses the joining of specified molecules or groups by a double bond.
Diastase is an enzyme group that is originally found in malt and it is produced when the germination of the seeds happens. Diastase transforms starch into maltose and after that, it converts this into glucose.
Hydrolases are hydrolytic enzymes, biochemical catalysts that use water to cleave chemical bonds, usually dividing a large molecule into two smaller molecules.