Final answer:
A transposon can enter a microbial genome through transformation, transduction, and conjugation, which are natural processes that allow for horizontal gene transfer and genetic diversity. option d is answer
Step-by-step explanation:
A transposon or insertion element can get into a microbial genome through several mechanisms:transformation, transduction, and conjugation. During transformation, a cell takes up DNA directly from its environment, which may then be integrated into its genome.
In transduction, DNA is transferred via a bacteriophage that injects a hybrid of its viral DNA and DNA from a previously infected cell. Lastly, conjugation involves the transfer of DNA between two cells through a mating bridge known as a pilus. All these mechanisms are naturally occurring processes that contribute to genetic diversity and could potentially lead to the spread of antibiotic resistance genes within microbial populations. option d is answer