DNA fragments are
(1) positively charged
(2) negatively charged
(4) either positively or negatively charged depending on their size
(2) DNA fragments are negatively charged molecules. The reason why DNA is negatively charged is the phosphate group that constitutes every nucleotide.
Thinking process - During the formation of phosphodiester bond, nucleotides retain one of the two negative charge, while the other is lost to form ester bond to new pentose.