The correct answer is option 'C': DNase.

Explanation:
- Enzymes are proteins that catalyze various biochemical reactions in living organisms. They are involved in breaking down and building up molecules in order to carry out specific functions.
- DNA, or deoxyribonucleic acid, is a double-stranded molecule that contains the genetic information of an organism. It is made up of nucleotides, which are composed of a sugar (deoxyribose), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine).
- DNA can be cleaved or cut at specific sites by enzymes known as nucleases. Nucleases are responsible for breaking the phosphodiester bonds that hold the nucleotides together.
- DNase, or deoxyribonuclease, is an enzyme that specifically cleaves DNA. It recognizes certain sequences or structures within the DNA molecule and breaks the phosphodiester bonds at those sites.
- DNase plays important roles in various biological processes. For example, it is involved in DNA repair, where it helps to remove damaged or mismatched bases from DNA strands. It also plays a role in DNA degradation, where it breaks down DNA into smaller fragments for recycling.
- DNase is also commonly used in molecular biology research and techniques. It is used to isolate DNA from other cellular components, to remove DNA contamination from RNA samples, or to digest unwanted DNA in experiments such as polymerase chain reaction (PCR) or DNA sequencing.
- Other enzymes, such as ligase, lipase, and RNase, have different functions and do not cleave DNA.
- Ligase is involved in the joining of DNA fragments, such as during DNA replication or in recombinant DNA technology.
- Lipase is an enzyme that breaks down lipids (fats) into fatty acids and glycerol.
- RNase, or ribonuclease, is an enzyme that specifically cleaves RNA. It is involved in RNA degradation, RNA processing, and other RNA-related processes.

In summary, the enzyme that cleaves DNA is DNase. It recognizes specific sites or structures within the DNA molecule and breaks the phosphodiester bonds, leading to the fragmentation of DNA. DNase plays important roles in various biological processes and is widely used in molecular biology research.