Structure of nucleic acids and replication of DNA — practice question

Which row shows the correct characteristics of the nitrogenous base adenine?

• Ahas a single ring structure ✓, is a purine ✓, joins its complementary base by three hydrogen bonds ✗, pairs with thymine ✗
• Bhas a single ring structure ✓, is a purine ✗, joins its complementary base by three hydrogen bonds ✓, pairs with thymine ✗
• Chas a single ring structure ✗, is a purine ✓, joins its complementary base by three hydrogen bonds ✗, pairs with thymine ✓
• Dhas a single ring structure ✗, is a purine ✗, joins its complementary base by three hydrogen bonds ✗, pairs with thymine ✓