Answer :
Final answer:
The correct option is a. Transmission. Transmission in biology refers to the movement of pathogens between hosts. It can happen through various means like direct contact or indirect exposure.
Explanation:
The correct option is a. Transmission. Transmission is defined as a pathogen moving from one host to another. It can occur through direct or indirect contact between hosts. For example, pathogens can be transmitted through activities like shaking hands, touching contaminated surfaces, or through the air.