Final answer:
The fossilization process involves the replacement of organic materials with minerals from the surrounding area.
Step-by-step explanation:
The best explanation of the fossilization process is a) replacement of organic materials, molecule by molecule, with minerals from the surrounding area. In this type of fossilization, the original skeletal material is substituted with secondary minerals such as silica, pyrite, dolomite, or hematite. This process can preserve fine cellular detail even though the composition changes. Other types of fossilization include permineralization, where minerals permeate the pore space and crystallize in porous tissue, and the preservation of remains through quick burial or preservation in sap.