Polymer properties vary due to which of the following factors?

The correct choice focuses on the monomers used and the conditions of polymerization as key factors that influence the properties of polymers. Different monomers can lead to variations in the structure and functionality of the resulting polymer. For instance, the properties can be significantly different if a polymer is made from different types of monomers – such as those with varying polarity, size, or functional groups – which affects characteristics like strength, flexibility, and resistance to heat or chemicals.

Additionally, the conditions under which polymerization occurs—such as temperature, pressure, and the presence of catalysts—can also influence the molecular structure of the polymer. These aspects can affect the arrangement of monomers, the degree of branching, and cross-linking within the polymer, all of which contribute to the final material's properties.

In summary, the combination of the monomers selected and the specific conditions during the polymerization process plays a crucial role in determining the physical and chemical properties of the resultant polymer.