Which of the following best describes the component of DNA labeled with an X in the diagram, if X is pointing to the phosphate group?

• A. A nitrogenous base that pairs with a complementary base on the opposite strand
• B. A hydrogen bond that connects two complementary bases
• C. A negatively charged group that links the 5' carbon of one deoxyribose to the 3' carbon of the next via a phosphodiester bond
• D. A five-carbon sugar that forms the backbone of the DNA strand

Answer: (C)

Verified step by step guidance

1. Identify the component labeled X in the DNA structure, which is indicated as the phosphate group.
2. Recall that the phosphate group in DNA is negatively charged and plays a crucial role in linking nucleotides together.
3. Understand that the phosphate group connects the 5' carbon of one deoxyribose sugar to the 3' carbon of the next sugar in the DNA strand.
4. Recognize that this connection forms a phosphodiester bond, which is essential for the sugar-phosphate backbone of DNA.
5. Compare the given answer choices to this description and select the one that correctly describes the phosphate group's role and characteristics.