The correct answer is Option D: Lyases.

Here's why:

Enzymes are biological catalysts that speed up chemical reactions in living organisms. They are classified into six main classes based on the type of reaction they catalyze.

Lyases are enzymes that catalyze the breaking of chemical bonds by means other than hydrolysis or oxidation. This typically results in the formation of a double bond or a new ring structure. They do not require water for the reaction and often produce a new double bond, ring, or a molecule of water.

Let's look at why the other options are incorrect:

Option A: Transferases These enzymes catalyze the transfer of functional groups (like methyl, phosphate, or amino groups) between molecules.

Option B: Oxidoreductases These enzymes catalyze oxidation-reduction reactions, where electrons are transferred between molecules.

Option C: Dehydrogenases These are a specific type of oxidoreductase that catalyze the removal of hydrogen atoms from a substrate.

In summary: Lyases are the enzymes responsible for breaking chemical bonds without using hydrolysis or oxidation, often creating double bonds or rings. This sets them apart from the other enzyme classes.