Which of the following is an example of vertical transmission of antibiotic resistance?

• A. A resistant parent cell dividing to produce daughter cells that inherit the resistance gene on the chromosome.
• B. A bacteriophage packaging a resistance gene and transducing it into a recipient cell.
• C. A plasmid moving from one bacterium to another through a conjugative pilus.
• D. A bacterium picking up naked DNA from the environment and incorporating it into its genome (transformation).

Answer: (A)