37. Which of the following is an example of how conjugation contributes to the spread of antibiotic resistance? (A) A bacterium spontaneously mutates to become resistant to penicillin. (B) An E. coli strain transfers a plasmid containing the blaKPC gene to a Klebsiella pneumoniae strain, making it resistant to carbapenems. (C) A bacterium acquires resistance through exposure to gradually increasing concentration of antibiotics. (D) A virus introduces antibiotic resistance genes into a bacterial population. (E) Bacteria develop resistance through adaptive changes in their metabolism.