Which type of microbes can be greatly reduced through effective hand washing?

The correct answer is transient microbes. These are the microbes that are present on the skin's surface due to external factors, such as touching contaminated surfaces or interacting with other individuals. Transient microbes are typically not a natural part of the skin's flora and can include pathogens that can cause infection if they enter the body. Effective hand washing is particularly designed to remove these types of microbes, thereby significantly reducing the risk of transmitting infections.

In contrast, resident flora refers to the normal microbiota that reside on the skin and are not typically pathogenic. They play a role in protecting the skin but are not easily removed through hand washing. Transitional microbes can refer to those that may transfer from one person to another or from surfaces to skin but are not the primary target of hygiene practices. Pathogenic microbes can be transient or part of resident flora, but they encompass a broader category that includes many types of microorganisms, not all of which are significantly reduced through hand washing alone. Thus, focusing on transient microbes specifically highlights the effectiveness of hand washing in minimizing infection risk.