Final answer:
The efflux pump is the most nonspecific resistance mechanism to a particular class of antimicrobials. It actively transports drugs out of the cell, preventing them from reaching their target sites.
Step-by-step explanation:
The efflux pump is the resistance mechanism that is most nonspecific to a particular class of antimicrobials. Efflux pumps are membrane proteins that actively transport antimicrobial drugs out of the cell, preventing the drugs from reaching their target sites and exerting their antibacterial effects. This resistance mechanism is commonly effective against a wide range of antimicrobials in multiple classes.