Final answer:
The removal of phosphate groups from a DNA sample does not significantly affect DNA length, as the length is determined by nucleotide pairs. Therefore, the answer is B. Phosphate.
Step-by-step explanation:
The removal of phosphate groups from a DNA sample will not significantly affect the length of DNA because DNA length is determined by the number of nucleotide pairs in the molecule. While the phosphate group and sugar together form the DNA backbone, DNA's length is dictated by the sequence of nucleobases (adenine, thymine, cytosine, and guanine) which pair up to form the steps of the DNA structure. The correct answer to the question 'Removal of which among these from a DNA sample will not significantly affect the length of DNA?' is therefore B. Phosphate.