Number of stereo centers present in linear and cyclic structures of glucose are respectively.

Step 1: Linear Glucose — In the open-chain form of glucose, there are four chiral centers located at carbons $\text{C2, C3, C4, and C5}$.

Step 2: Cyclic Glucose — When the ring closes, the carbonyl carbon ($\text{C1}$) becomes a new chiral center (the anomeric carbon), creating $\alpha$ and $\beta$ forms.

Step 3: Conclusion — Thus, the total count of stereocenters increases from four in the linear form to five in the cyclic form. Correct option is (a).

Key Point: The creation of a new chiral center during cyclization is the reason for the existence of anomers.