The term anomers of glucose refers to

When an aldohexose such as glucose forms its cyclic hemi-acetal, the aldehydic carbon $$C-1$$ becomes a new stereogenic centre called the anomeric carbon.

Two stereoisomers are possible at this centre: one in which the $$OH$$ on $$C-1$$ is trans to the $$CH_2OH$$ group at $$C-5$$ (the $$\alpha$$ form) and one in which they are cis (the $$\beta$$ form). These two forms are called anomers.

Thus, anomers are defined as “isomers that differ only in configuration around the anomeric carbon (here $$C-1$$ for glucose).” They are not mirror images, they do not involve any other carbon atom, and they are not $$D/L$$ opposites.

Checking each option:

Option A mentions difference at both $$C-1$$ and $$C-4$$ $$\rightarrow$$ involves an extra carbon, so it is incorrect.

Option B is simply a racemic mixture of $$D$$ and $$L$$ forms, not related to the anomeric centre → incorrect.

Option C talks about enantiomers (mirror images at all chiral centres), not configuration change at only one centre → incorrect.

Option D accurately states that anomers “differ in configuration at carbon one” → correct.

Final Answer: Option D which is: isomers of glucose that differ in configuration at carbon one ($$C-1$$).