This forms the crystalline core inside peroxisome

The correct option is "highly condensed oxidative enzymes".

Peroxisomes are membrane-bound organelles found in the cytoplasm of eukaryotic cells. They play a crucial role in various metabolic processes, including the beta-oxidation of very-long-chain fatty acids and the detoxification of hydrogen peroxide ($H_2{O}_2$).

In many animal and plant cells, peroxisomes contain a distinct, dense, crystalline core (also known as a nucleoid) when viewed under an electron microscope. This crystalline core is not composed of inorganic salts or lipids; rather, it is a high-density, crystalline array of proteins.
Specifically, these proteins are highly condensed oxidative enzymes, most notably urate oxidase (uricase), which is involved in the purine degradation pathway. The high concentration of these enzymes leads to their crystallization, forming the prominent core structure inside the organelle.