Biomolecules

Step 1: Evaluate each statement.
(A) Guanine is a purine → correct.
(B) Only glycine is achiral; proline is chiral → incorrect.
(C) DNA has β-glycosidic bonds connecting nitrogenous base and deoxyribose sugar → correct.
(D) Sucrose is non-reducing because both anomeric carbons are involved in glycosidic linkage → correct.
Step 2: Conclusion.
Thus, the correct statements are (A), (C), and (D).