You isolate a bacterium that can transfer genes to other bacteria without being in direct contact.You isolate the medium in which this bacterium is growing (being very careful not to leave any of the bacteria in the medium), and treat it with DNAse (an enzyme that digests DNA), then add new bacteria and allow them to grow in this medium.You find these bacteria have NOT acquired new genes. The genes are most likely transferring by... a-conjugation b-transduction c-transformation D-all of the other answers are correct