Which of the following actions should a medical assistant take to prevent the transmission of disease?

This action is counterproductive to disease prevention; long fingernails can harbor dirt and bacteria, increasing the risk of transmitting infections. Proper hygiene includes keeping nails short and clean, typically no longer than the fingertip, to minimize this risk.

While wearing clear nail polish may appear more hygienic, it does not inherently prevent disease transmission. The presence of any nail polish can potentially chip and create crevices for bacteria to grow, while the focus should instead be on maintaining clean, short nails and effective hand hygiene practices.

Chlorhexidine is an antimicrobial agent that can be effective in certain situations, particularly for surgical hand scrubs. However, for routine hand hygiene, especially in non-surgical settings, alcohol-based hand disinfectants are generally recommended due to their convenience and rapid action against pathogens.