Answer: 3 and 5 only
Explanation:
Adenine is a purine nitrogenous base and it pairs with thymine which is a pyrimidine nitrogenous base with a triple hydrogen bond in a DNA structure. The adenine binds with thymine directly and indirectly with a deoxyribose sugar which is attached with it in the back it forms the part of sugar phosphate backbone and in the front hydrogen bonding helps in the stabilizing the DNA structure by binding two separate strands of DNA in a stable double helical structure.
