Please answer as soon as possible!

The best answer is B.

DNA has a nitrogenous base called Thymine but  RNA does not. Instead RNA has Uracil in its structure, thus in DNA, thymine pairs with Adenine but in RNA, Uracil pairs with adenine.

Other differences include :

1. DNA is limited to the nucleus but RNA  can move out to the cell cytoplasm.

2.There is only one type of DNA but 3 types of RNA namely mRNA, tRNA and rRNA.

3. DNA contains the pentose sugar deoxyribose while RNA contains the pentose sugar ribose.

4. DNA is double stranded while RNA is single stranded.

5. DNA stores hereditary information while RNA serves to ferry and translate a copy of this information.