In Recombinant DNA Methods, the Term "Vector" Can Refer to ________

In recombinant DNA methods, the term "vector" can refer to ________.

A) the enzyme (endonuclease) that cuts DNA into restriction fragments
B) the "sticky end" of a DNA fragment
C) circular endogenous DNA in mammalian cell
D) a plasmid used to transfer DNA into a living cell
E) a DNA probe used to identify a particular gene