Polymers

Bakelite is formed by condensation polymerisation of phenol and formaldehyde in the presence of either an acid or a base catalyst. The initially formed o- and p-hydroxy methylphenol derivatives further react to form a linear polymer called novolac which on heating with formaldehyde undergoes cross linkage to form an infusible solid called bakelite.

Anomers are a type of stereoisomers that differ in configuration only at the anomeric carbon. The anomeric carbon is the carbonyl carbon in the open-chain form that becomes a stereocenter when the monosaccharide cyclizes to form a cyclic structure. Looking at the structures: - Structure I and Structure III are anomers because they differ in the configuration at the anomeric carbon (the carbon that was originally part of the carbonyl group in the open-chain form). - Structure II is not an anomer of I or III, as it has a different configuration at a different carbon and is not derived from a similar open-chain form. Therefore, Structures I and III are the two anomers. Thus, the correct answer is (D)